Mr. Justice Stevens
delivered the opinion of the Court.
To extinguish the last group of conflicting claims to lands lying west of the Cascade Mountains and north of the Columbia River in what is now the State of Washington, the United States entered into a series of treaties with Indian tribes in 1854 and 1855. The Indians relinquished their interest in most of the Territory in exchange for monetary payments. In addition, certain relatively small parcels of land were reserved for their exclusive use, and they were afforded other guarantees, including protection of their “right of taking fish, at all usual and accustomed grounds and stations ... in common with all citizens of the Territory.” 10 Stat. 1133.
The principal question presented by this litigation concerns the character of that treaty right to take fish. Various other issues are presented, but their disposition depends on the answer to the principal question. Before answering any of these questions, or even stating the issues with more precision, we shall briefly describe the anadromous fisheries of the Pacific Northwest, the treaty negotiations, and the principal components of the litigation complex that led us to grant these three related petitions for certiorari.
I
Anadromous fish hatch in fresh water, migrate to the ocean where they are reared and reach mature size, and eventually complete their life cycle by returning to the fresh-water place of their origin to spawn. Different species have different life cycles, some spending several years and traveling great distances in the ocean before returning to spawn and some even returning to spawn on more than one occasion before dying. 384 F. Supp. 312, 384, 405. See Comment, State Power and the Indian Treaty Right to Fish, 59 Calif. L. Rev. 485, 501, and n. 99 (1971). The regular habits of these fish make their “runs” predictable; this predictability in turn makes it possible for both fishermen and regulators to forecast and to control the number of fish that will be caught or “harvested.” Indeed, as the terminology associated with it suggests, the management of anadromous fisheries is in many ways more akin to the cultivation of “crops” — with its relatively high degree of predictability and productive stability, subject mainly to sudden changes in climatic patterns — than is the management of most other commercial and sport fisheries. 384 F. Supp., at 351, 384.
Regulation of the anadromous fisheries of the Northwest is nonetheless complicated by the different habits of the various species of salmon and trout involved, by the variety of methods of taking the fish, and by the fact that a run of fish may pass through a series of different jurisdictions. Another complexity arises from the fact that the State of Washington has attempted to reserve one species, steelhead trout, for sport fishing and therefore conferred regulatory jurisdiction over that species upon its Department of Game, whereas the various species of salmon are primarily harvested by commercial fishermen and are managed by the State’s Department of Fisheries. Id., at 383-385, 389-399. Moreover, adequate regulation not only must take into account the potentially conflicting interests of sport and commercial fishermen, as well as those of Indian and nontreaty fishermen, but also must recognize that the fish runs may be harmed by harvesting either too many or too few of the fish returning to spawn. Id., at 384, 390.
The anadromous fish constitute a natural resource of great economic value to the State of Washington. Millions of salmon, with an average weight of from 4 or 5 to about 20 pounds, depending on the species, are harvested each year. Over 6,600 nontreaty fishermen and about 800 Indians make their livelihood by commercial fishing; moreover, some 280,000 individuals are licensed to engage dn sport fishing in the State. Id., at 387. See id., at 399.
II
One hundred and twenty-five years ago when the relevant treaties were signed, anadromous fish were even more important to most of the population of western Washington than they are today. At that time, about three-fourths of the approximately 10,000 inhabitants of the area were Indians. Although in some respects the cultures of the different tribes varied — some bands of Indians, for example, had little or no tribal organization while others, such as the Makah and the Yakima, were highly organized — all of them shared a vital and unifying dependence on anadromous fish. Id., at 350. See Puyallup Tribe v. Washington Game Dept., 433 U. S. 165, 179 (Brennan, J., dissenting in part).
Religious rites were intended to insure the continual return of the salmon and the trout; the seasonal and geographic variations in the runs of the different species determined the movements of the largely nomadic tribes. 384 F. Supp., at 343, 351, 382; 459 F. Supp. 1020,1079; 520 F. 2d 676, 682. Fish constituted a major part of the Indian diet, was used for commercial purposes, and indeed was traded in substantial volume. The Indians developed food-preservation techniques that enabled them to store fish throughout the year and to transport it over great distances. 384 F. Supp., at 351. They used a wide variety of methods to catch fish, including the precursors of all modern netting techniques. Id., at 351, 352, 362, 368, 380. Their usual and accustomed fishing places were numerous and were scattered throughout the area, and included marine as well as fresh-water areas. Id., at 353, 360, 368-369.
All of the treaties were negotiated by Isaac Stevens, the first Governor and first Superintendent of Indian Affairs of the Washington Territory, and a small group of advisers. Contemporaneous documents make it clear that these people recognized the vital importance of the fisheries to the Indians and wanted to protect them from the risk that non-Indian settlers might seek to monopolize their fisheries. Id., at 355, 363. There is no evidence of the precise understanding the Indians had of any of the specific English terms and phrases in the treaty. Id., at 356. It is perfectly clear, however, that the Indians were vitally interested in protecting their right to take fish at usual and accustomed places, whether on or off the reservations, id., at 355, and that they were invited by the white negotiators to rely and in fact did rely heavily on the good faith of the United States to protect that right.
Referring to the negotiations with the Yakima Nation, by far the largest of the Indian tribes, the District Court found:
“At the treaty council the United States negotiators promised, and the Indians understood, that the Yakimas would forever be able to continue the same off-reservation food gathering and fishing practices as to time, place, method, species and extent as they had or were exercising. The Yakimas relied on these promises and they formed a material and basic part of the treaty and of the Indians’ understanding of the meaning of the treaty.” Id., at 381 (record citations omitted).
See also id., at 363 (similar finding regarding negotiations with the Makah Tribe).
• The Indians understood that non-Indians would also have the right to fish at their off-reservation fishing sites. But this was not understood as a significant limitation on their right to take fish. Because of the great abundance of fish and the limited population of the area, it simply was not contemplated that either party would interfere with the other’s fishing rights. The parties accordingly did not see the need and did not intend to regulate the taking of fish by either Indians or non-Indians, nor was future regulation foreseen.. Id., at 334, 355, 357.
Indeed, for several decades after the treaties were signed, Indians continued to harvest most of the fish taken from the waters of Washington, and they moved freely about the Territory and later the State in search of that resource. Id., at 334. The size of the fishery resource continued to obviate the need during the period to regulate the taking of fish by either Indians or non-Indians. Id., at 352. Not until major economic developments in canning and processing occurred in the last few years of the 19th century did a significant non-Indian fishery develop. It was as a consequence of these developments, rather than of the treaty, that non-Indians began to dominate the fisheries and eventually to exclude most Indians from participating in it — a trend that was encouraged by the onset of often discriminatory state regulation in the early decades of the 20th century. Id., at 358, 394, 404, 407; 459 F. Supp., at 1032.
In sum, it is fair to conclude that when the treaties were negotiated, neither party realized or intended that their agreement would determine whether, and if so how, a resource that had always been thought inexhaustible would be allocated between the native Indians and the incoming settlers when it later became scarce.
Ill
Unfortunately, that resource has now become scarce, and the meaning of the Indians' treaty right to take fish has accordingly become critical. The United States Court of Appeals for the Ninth Circuit and the Supreme Court of the State of Washington have issued conflicting decisions on its meaning. In addition, their holdings raise important ancillary questions that will appear from a brief review of this extensive litigation.
The federal litigation was commenced in the United States District Court for the Western District of Washington in 1970. The United States, on its own behalf and as trustee for seven Indian tribes, brought suit against the State of Washington seeking an interpretation of the treaties and an injunction requiring the State to protect the Indians’ share of the anadro-mous fish runs. Additional Indian tribes, the State’s Fisheries and Game Departments, and one commercial fishing group, were joined as parties at various stages of the proceedings, while various other agencies and groups, including all of the commercial fishing associations that are parties here, participated as amici curiae. 384 F. Supp., at 327, 328, and n. 4; 459 F. Supp., at 1028.
During the extensive pretrial proceedings, four different interpretations of the critical treaty language were advanced. Of those, three proceeded from the assumption that the language required some allocation to the Indians of a share of the runs of fish passing through their traditional fishing areas each year. The tribes themselves contended that the treaties had reserved a pre-existing right to as many fish as their commercial and subsistence needs dictated. The United States argued that the Indians were entitled either to a 50% share of the “harvestable” fish that originated in and returned to the “case area” and passed through their fishing places, or to their needs, whichever was less. The Department of Fisheries agreed that the Indians were entitled to “a fair and equitable share” stated in terms of a percentage of the har-vestable salmon in the area; ultimately it proposed a share of “one-third.”
Only the Game Department thought the treaties provided no assurance to the Indians that they could take some portion of each run of fish. That agency instead argued that the treaties gave the Indians no fishing rights not enjoyed by non-treaty fishermen except the two rights previously recognized by decisions of this Court — the right of access over private lands to their usual and accustomed fishing grounds, see Seufert Bros. Co. v. United States, 249 U. S. 194; United States v. Winans, 198 U. S. 371, and an exemption from the payment of license fees. See Tulee v. Washington, 315 U. S. 681.
The District Court agreed with the parties who advocated an allocation to the Indians, and it essentially agreed with the United States as to what that allocation should be. It held that the Indians were then entitled to a 45% to 50% share of the harvestable fish that will at some point pass through recognized tribal fishing grounds in the case area. The share was to be calculated on a river-by-river, run-by-run basis, subject to certain adjustments. Fish caught by Indians for ceremonial and subsistence purposes as well as fish caught within a reservation were excluded from the calculation of the tribes’ share. In addition, in order to compensate for fish caught outside of the case area, i. e., beyond the State’s jurisdiction, the court made an “equitable adjustment” to increase the allocation to the Indians. The court left it to the individual tribes involved to agree among themselves on how best to divide the Indian share of runs that pass through the usual and accustomed grounds of more than one tribe, and it postponed until a later date the proper accounting for hatchery-bred fish. 384 F. Supp., at 416-417; 459 F. Supp., at 1129. With a slight modification, the Court of Appeals for the Ninth Circuit affirmed, 520 F. 2d 676, and we denied certiorari, 423 U. S. 1086.
The injunction entered by the District Court required the Department of Fisheries (Fisheries) to adopt regulations protecting the Indians' treaty rights. 384 F. Supp., at 416-417. After the new regulations were promulgated, however, they were immediately challenged by private citizens in suits commenced in the Washington state courts. The State Supreme Court, in two cases that are here in consolidated form in No. 77-983, ultimately held that Fisheries could not comply with the federal injunction. Puget Sound Gillnetters Assn. v. Moos, 88 Wash. 2d 677, 565 P. 2d 1151 (1977); Fishing Vessel Assn. v. Tollefson, 89 Wash. 2d 276, 571 P. 2d 1373 (1977).
As a matter of federal law, the state court first accepted the Game Department's and rejected the District Court’s interpretation of the treaties and held that they did not give the Indians a right to a share of the fish runs, and second concluded that recognizing special rights for the Indians would violate the Equal Protection Clause of the Fourteenth Amendment. The opinions might also be read to hold, as a matter of state law, that Fisheries had no authority to issue the regulations because they had a purpose other than conservation of the resource. In this Court, however, the Attorney General of the State disclaims the adequacy and independence of the state-law ground and argues that the state-law authority of Fisheries is dependent on the answers to the two federal-law questions discussed above. Brief for State of Washington 99. See n. 34, infra. We defer to that interpretation, subject, of course, to later clarification by the State Supreme Court. Because we are also satisfied that the constitutional holding is without merit our review of the state court’s judgment will be limited to the treaty issue.
When Fisheries was ordered by the state courts to abandon its attempt to promulgate and enforce regulations in compliance with the federal court’s decree — and when the Game Department simply refused to comply- — the District Court entered a series of orders enabling it, with the aid of the United States Attorney for the Western District of Washington and various federal law enforcement agencies, directly to supervise those aspects of the State’s fisheries necessary to the preservation of treaty fishing rights. 459 F. Supp. 1020. The District Court’s power to take such direct action and, in doing so, to enjoin persons who were not parties to the proceeding was affirmed by the United States Court of Appeals for the Ninth Circuit. 573 F. 2d 1123. That court, in a separate opinion, 573 F. 2d 1118, also held that regulations of the International Pacific Salmon Fisheries Commission posed no impediment to the District Court’s interpretation of the treaty language and to its enforcement- of that interpretation. Subsequently, the District Court entered -an enforcement order regarding the salmon fisheries for the 1978 and subsequent seasons, which, prior to our issuance of a writ of cer-tiorari to review the case, was pending on appeal in the Court of Appeals. App. 486-490.
Because of the widespread defiance of the District Court’s orders, this litigation has assumed unusual significance. We granted certiorari in the state and federal cases to interpret this important treaty provision and thereby to resolve the conflict between the state and federal courts regarding what, if any, right the Indians have to a share of the fish, to address the implications of international regulation of the fisheries in the area, and to remove any doubts about the federal court’s power to enforce its orders. 439 U. S. 909.
IV
The treaties secure a “right of taking fish.” The pertinent articles provide:
“The right of taking fish, at all usual and accustomed grounds and stations, is further secured to said Indians, in common with all citizens of the Territory, and of erecting temporary houses for the purpose of curing, together with the privilege of hunting, gathering roots and berries, and pasturing their horses on open and unclaimed lands: Provided, however, That they shall not take shell fish from any beds staked or cultivated by citizens.”
At the time the treaties were executed there was a great abundance of fish and a relative scarcity of people. No one had any doubt about the Indians’ capacity to take as many fish as they might need. Their right to take fish could therefore be adequately protected by guaranteeing them access to usual and accustomed fishing sites which could be — and which for decades after the treaties were signed were — comfortably shared with the incoming settlers.
Because the sparse contemporaneous written materials refer primarily to assuring access to fishing sites “in common with all citizens of the Territory,” the State of Washington and the commercial fishing associations, having all adopted the Game Department’s original position, argue that it was merely access that the negotiators guaranteed. It is equally plausible to conclude, however, that the specific provision for access was intended to secure a greater right — a right to harvest a share of the runs of anadromous fish that at the time the treaties were signed were so plentiful that no one could question the Indians’ capacity to take whatever quantity they needed. Indeed, a fair appraisal of the purpose of the treaty negotiations, the language of the treaties, and this Court’s prior construction of the treaties, mandates that conclusion.
A treaty, including one between the United States and an Indian tribe, is essentially a contract between two sovereign nations. E. g., Lone Wolf v. Hitchcock, 187 U. S. 553. When the signatory nations have not been at war and neither is the vanquished, it is reasonable to assume that they negotiated as equals at arm’s length. There is no reason to doubt that this assumption applies to the treaties at issue here. See 520 F. 2d, at 684.
Accordingly, it is the intention of the parties, and not solely that of the superior side, that must control any attempt to interpret the treaties. When Indians are involved, this Court has long given special meaning to this rule. It has held that the United States, as the party with the presumptively superior negotiating skills and superior knowledge of the language in which the treaty is recorded, has a responsibility to avoid taking advantage of the other side. “[T]he treaty must therefore be construed, not according to the technical meaning of its words to learned lawyers, but in the sense in which they would naturally be understood by the Indians.” Jones v. Meehan, 175 U. S. 1, 11. This rule, in fact, has thrice been explicitly relied on by the Court in broadly interpreting these very treaties in the Indians' favor. Tulee v. Washington, 315 U. S. 681; Seufert Bros. Co. v. United States, 249 U. S. 194; United States v. Winans, 198 U. S. 371. See also Washington v. Yakima Indian Nation, 439 U. S. 463, 484.
Governor Stevens and his associates were well aware of the “sense” in which the Indians were likely to view assurances regarding their fishing rights. During the negotiations, the vital importance of the fish to the Indians was repeatedly emphasized by both sides, and the Governor's promises that the treaties would protect that source of food and commerce were crucial in obtaining the Indians’ assent. See supra, at 666-668. It is absolutely clear, as Governor Stevens himself said, that neither he nor the Indians intended that the latter “should be excluded from their ancient fisheries,” see n. 9, supra, and it is accordingly inconceivable that either party deliberately agreed to authorize future settlers to crowd the Indians out of any meaningful use of their accustomed places to fish. That each individual Indian would share an “equal opportunity” with thousands of newly arrived individual settlers is totally foreign to the spirit of the negotiations. Such a “right,” along with, the $207,500 paid the Indians, would hardly have been sufficient to compensate them for the millions of acres they ceded to the Territory.
It is true that the words “in common with” may be read either as nothing more than a guarantee that individual Indians would have the same right as individual non-Indians or as securing an interest in the fish runs themselves. If we were to construe these words by. reference to 19th-century property concepts, we might accept the former interpretation, although even “learned lawyers” of the day would probably have offered differing interpretations of the three words. But we think greater importance should be given to the Indians’ likely understanding of the other words in the treaties and especially the reference to the “right of taking fish” — a right that had no special meaning at common law but that must have had obvious significance to the tribes relinquishing a portion of their pre-existing rights to the United States in return for this promise. This language is particularly meaningful in the context of anadromous fisheries — which were not the focus of-the common law — because of the relative predictability of the “harvest.” In this context, it makes sense to say that a party has a right to “take” — rather than merely the “opportunity” to try to catch — some of the large quantities of fish that will almost certainly be available at a given place at a given time.
This interpretation is confirmed by additional language in the treaties. The fishing clause speaks of “securing” certain fishing rights, a term the Court has previously interpreted as synonymous with “reserving” rights previously exercised. Winans, 198 U. S., at 381. See also New York ex rel. Kennedy v. Becker, 241 U. S. 556, 563-564. Because the Indians had always exercised the right to meet their subsistence and commercial needs by taking fish from treaty area waters, they would be unlikely to perceive a “reservation” of that right as merely the chance, shared with millions of other citizens, occasionally to dip their nets into the territorial waters. Moreover, the phrasing of the clause quite clearly avoids placing each individual Indian on an equal footing with each individual citizen of the State. The referent of the “said Indians” who are to share the right of taking fish with “all citizens of the Territory” is not the individual Indians but the various signatory “tribes and bands of Indians” listed in the opening article of each treaty. Because it was the tribes that were given a right in common with non-Indian citizens, it is especially likely that a class right to a share of fish, rather than a personal right to attempt to land fish, was intended.
In our view, the purpose and language of the treaties are unambiguous; they secure the Indians’ right to take a share of each run of fish that passes through tribal fishing areas. But our prior decisions provide an even more persuasive reason why this interpretation is not open to question. For notwithstanding the bitterness that this litigation has engendered, the principal issue involved is virtually a “matter decided” by our previous holdings.
The Court has interpreted the fishing clause in these treaties on six prior occasions. In all of these cases the Court placed a relatively broad gloss on the Indians’ fishing rights and — more or less explicitly — rejected the State’s “equal opportunity” approach; in the earliest and the three most recent cases, moreover, we adopted essentially the interpretation that the United States is reiterating here.
In United States v. Winans, supra, the respondent, having acquired title to property on the Columbia River and having obtained a license to use a “fish wheel” — a device capable of catching salmon by the ton and totally destroying a run of fish — asserted the right to exclude the Yakimas from one of their “usual and accustomed” places. The Circuit Court for the District of Washington sustained respondent, but this Court reversed. The Court initially rejected an argument that is analogous to the “equal opportunity” claim now made by the State:
“[I]t was decided [below] that the Indians acquired no rights but what any inhabitant of the Territory or State would have. Indeed, acquired no rights but such as they would have without the treaty. This is certainly an impotent outcome to negotiations and a convention; which seemed to promise more and give the word of the Nation for more. . . . How the treaty in question was understood may be gathered from the circumstances.
“The right to resort to the fishing places in controversy was a part of larger rights possessed by the Indians, upon the exercise of which there was not a shadow of impediment, and which were not much less necessary to the existence of the Indians than the atmosphere they breathed. New conditions came into existence, to which those rights had to be accommodated. Only a limitation of them, however, was necessary and intended, not a taking away. In other words, the treaty was not a grant of rights to the Indians, but a grant of rights from them— a reservation of those not granted. And the form of the instrument and its language was adapted to that purpose. . . . There was an exclusive right to fishing reserved within certain boundaries. There was a right outside of those boundaries reserved fin common with citizens of the Territory.' As a mere right, it was not exclusive in the Indians. Citizens might share it, but the Indians were secured in its enjoyment by a special provision of means for its exercise. They were given The right of taking fish at all usual and accustomed places/ and the right 'of erecting temporary buildings for curing them.’ The contingency of the future ownership of the lands, therefore, was foreseen and provided for — in other words, the Indians were given a right in the land — the right of crossing it to the river — the right to occupy it to the extent and for the purpose mentioned. No other conclusion would give effect to the treaty.” 198 U. S., at 380-381.
See also Seufert Bros., 249 U. S., at 198, and Tulee, 315 U. S., at 684, both of which repeated this analysis, in holding that treaty Indians had rights, “beyond those which other citizens may enjoy,” to fish without paying license fees in ceded areas and even in accustomed fishing places lying outside of the lands ceded by the Indians. See n. 22, supra.
But even more significant than the language in Winans is its actual disposition. The Court not only upheld the Indians’ right of access to respondent’s private property but also ordered the Circuit Court on remand to devise some “adjustment and accommodation” that would protect them from total exclusion from the fishery. 198 Ü. S., at 384. Although the accommodation it suggested by reference to the Solicitor General’s brief in the case is subject to interpretation, it clearly included removal of enough of the fishing wheels to enable some fish to escape and be available to Indian fishermen upstream. Brief for United States, O. T. 1904, No. 180, pp. 54 — 56. In short, it assured the Indians a share of the fish.
In the more recent litigation over this treaty language between the Puyallup Tribe and the Washington Department of Game, the Court in the context of a dispute over rights to the run of steelhead trout on the Puyallup River reaffirmed both of the holdings that may be drawn from Winans — the treaty guarantees the Indians more than simply the “equal opportunity” along with all of the citizens of the State to catch fish, and it in fact assures them some portion of each relevant run. But the three Puyallup cases are even more explicit; they clearly establish the principle that neither party to the treaties may rely on the State’s regulatory powers or on property law concepts to defeat the other’s right to a “fairly apportioned” share of each covered run of harvestable anadromous fish.
In Puyallup I, the Court sustained the State’s power to impose nondiscriminatory regulations on treaty fishermen so long as they were “necessary” for the conservation of the various species. In so holding, the Court again explicitly rejected the equal-opportunity theory. Although nontreaty fishermen might be subjected to any reasonable state fishing regulation serving any legitimate purpose, treaty fishermen are immune from all regulation save that required for conservation.
When the Department of Game sought to impose a total ban on commercial net fishing for steelhead, the Court held in Puyallup II that such regulation was not a “reasonable and necessary conservation measure” and would deny the Indians their “fairly apportioned” share of the Puyallup River run. 414 U. S. 44, 45, 48. Although under the challenged regulation every individual fisherman would have had an equal opportunity to use a hook and line to land the steelhead, most of the fish would obviously have been caught by the 145,000 nontreaty licensees rather than by the handful of treaty fishermen. This Court vindicated the Indians’ treaty right to “take fish” by invalidating the ban on Indian net fishing and remanding the case with instructions to the state courts to determine the portion of harvestable steelhead that should be allocated to net fishing by members of the tribe. Id., at 48-49. Even if Winans had not already done so, this unanimous holding foreclosed the basic argument that the State is now advancing.
On remand, the Washington state courts held that 45% of the steelhead run was allocable to commercial net fishing by the Indians. We shall later discuss how that specific percentage was determined; what is material for present purposes is the recognition, upheld by this Court in Puyallup III, that the treaty secured the Tribe’s right to a substantial portion of the run, and not merely a right to compete with nontreaty fishermen on an individual basis.
Puyallup III also made it clear that the Indians could not rely on their treaty right to exclude others from access to certain fishing sites to deprive other citizens of the State of a “fair apportionment” of the runs. For- although it is clear that the Tribe may exclude non-Indians from access to fishing within the reservation, we unequivocally rejected the Tribe’s claim to an untrammeled right to take as many of the steel-head running through its reservation as it chose. In support of our holding that the State has regulatory jurisdiction over on-reservation fishing, we reiterated Mr. Justice Douglas’ statement for the Court in Puyallup II that the “Treaty does not give the Indians a federal right to pursue the last living steelhead until it enters their nets.” 414 U. S., at 49. It is in this sense that treaty and nontreaty fishermen hold “equal” rights. For neither party may deprive the other of a “fair share” of the runs.
Not only all six of our cases interpreting the relevant treaty language but all federal courts that have interpreted the treaties in recent times have reached the foregoing conclusions, see Sohappy v. Smith, 302 F. Supp. 899, 908, 911 (Ore. 1969) (citing cases), as did the Washington Supreme Court itself prior to the present litigation. State v. Satiacum, 50 Wash. 2d 513, 523-524, 314 P. 2d 400, 406 (1957), A like interpretation, moreover, has been followed by the Court with respect to hunting rights explicitly secured by treaty to Indians “ ‘in common with all other persons,’ ” Antoine v. Washington, 420 U. S. 194, 205-206, and to water rights that were merely implicitly secured to the Indians by treaties reserving land— treaties that the Court enforced by ordering an apportionment to the Indians of enough water to meet their subsistence and cultivation needs. Arizona v. California, 373 U. S. 546, 598-601, following United States v. Powers, 305 U. S. 527, 528-533; Winters v. United States, 207 U. S. 564, 576.
The purport of our cases is clear. Nontreaty fishermen may not rely on property law concepts, devices such as the fish wheel, license fees, or general regulations to deprive the Indians of a fair share of the relevant runs of anadromous fish in the case area. Nor may treaty fishermen rely on their exclusive right of access to the reservations to destroy the rights of other “citizens of the Territory.” Both sides have a right, secured by treaty, to take a fair share of the available fish. That, we think, is what the parties to the treaty intended when they secured to the Indians the right of taking fish in common with other citizens.
Y
We also agree with the Government that an equitable measure of the common right should initially divide the harvesta-ble portion of each run that passes through a “usual and accustomed” place into approximately equal treaty and non-treaty shares, and should then reduce the treaty share if tribal needs may be satisfied by a lesser amount. Although this method of dividing the resource, unlike the right to some division, is not mandated by our prior cases, it is consistent with the 45%-55% division arrived at by the Washington state courts, and affirmed by this Court, in Puyallup III with respect to the steelhead run on the Puyallup River. The trial court in the Puyallup litigation reached those figures essentially by starting with a 50% allocation based on the Indians’ reliance on the fish for their livelihoods and then adjusting slightly downward due to other relevant factors. App. to Pet. for Cert. in Puyallup III, O. T. 1976, No. 76-423, pp. C-56 to C-57. The District Court took a similar tack in this case, i. e., by starting with a 50-50 division and adjusting slightly downward on the Indians’ side when it became clear that they did not need a full 50%. 384 F. Supp., at 402, 416-417 ; 459 F. Supp., at 1101; 573 F. 2d, at 1129.
The division arrived at by the District Court is also consistent with our earlier decisions concerning Indian treaty rights to scarce natural resources. In those cases, after determining that at the time of the treaties the resource involved was necessary to the Indians’ welfare, the Court typically ordered a trial judge or special master, in his discretion, to devise some apportionment that assured that the Indians’ reasonable livelihood needs would be met. Arizona v. California, supra, at 600; Winters, supra. See Winans, 198 U. S., at 384. This is precisely what the District Court did here, except that it realized that some ceiling should be placed on the Indians’ apportionment to prevent their needs from exhausting the entire resource and thereby frustrating the treaty right of “all [other] citizens of the Territory.”
Thus, it first concluded that at the time the treaties were signed, the Indians, who comprised three-fourths of the territorial population, depended heavily on anadromous fish as a source of food, commerce, and cultural cohesion. Indeed, it found that the non-Indian population depended on Indians to catch the fish that the former consumed. See supra, at 664r-669, and n. 7. Only then did it determine that the Indians’ present-day subsistence and commercial needs should be met, subject, of course, to the 50% ceiling. 384 F. Supp., at 342-343.
It bears repeating, however, that the 50% figure imposes a maximum but not a minimum allocation. As in Arizona v. California and its predecessor cases, the central principle here must be that Indian treaty rights to a natural resource that once was thoroughly and exclusively exploited by the Indians secures so much as, but no more than, is necessary to provide the Indians with a livelihood — that is to say, a moderate living. Accordingly, while the maximum possible allocation to the Indians is fixed at 50%, the minimum is not; the latter will, upon proper submissions to the District Court, be modified in response to changing circumstances. If, for example, a tribe should dwindle to just a few members, or if it should find other sources of support that lead it to abandon its fisheries, a 45% or 50% allocation of an entire run that passes through its customary fishing grounds would be manifestly inappropriate because the livelihood of the tribe under those circumstances could not reasonably require an allotment of a large number of fish.
Although the District Court’s exercise of its discretion, as slightly modified by the Court of- Appeals, see n. 18, supra, is in most respects unobjectionable, we are not satisfied that all of the adjustments it made to its division are consistent with the preceding analysis.
The District Court determined that the fish taken by the Indians on their reservations should not be counted against their share. It based this determination on the fact that Indians have the exclusive right under the treaties to fish on their reservations. But this fact seems to us to have no greater significance than the fact that some nontreaty fishermen may have exclusive access to fishing sites that are not “usual and accustomed” places. Shares in the fish runs should not be affected by the place where the fish are taken. Cf. Puyallup III, 433 U. S., at 173-177. We therefore disagree with the District Court’s exclusion of the Indians’ on-reservation catch from their portion of the runs.
This same rationale, however, validates the Court-of-Appeals-modified equitable adjustment for fish caught outside the jurisdiction of the State by nontreaty fishermen from the State of Washington. See n. 18, supra, and accompanying text. So long as they take fish from identifiable runs that are destined for traditional tribal fishing grounds, such persons may not rely on the location of their take to justify excluding it from their share. Although it is true that the fish involved are caught in waters subject to the jurisdiction of the United States, rather than of the State, see 16 U. S. C.. §§ 1811, 1812, the persons catching them are nonetheless “citizens of the Territory” and as such the beneficiaries of thé Indians’ reciprocal grant of land in the treaties as well as the persons expressly named in the treaties as sharing fishing rights with the Indians. Accordingly, they may justifiably be treated differently from nontreaty fishermen who are not citizens of Washington. The statutory provisions just cited are therefore important in this context only because they clearly place a responsibility on the United States, rather than the State, to police the take of fish in the relevant waters by Washington citizens insofar as is necessary to assure compliance with the treaties.
On the other hand, as long as there are enough fish to satisfy the Indians’ ceremonial and subsistence needs, we see no justification for the District Court’s exclusion from the treaty share of fish caught for these purposes. We need not now decide whether priority for such uses would be required in a period of short supply in order to carry out the purposes of the treaty. See 384 F. Supp., at 343. For present purposes, we merely hold that the total catch — rather than the commercial catch — is the measure of each party’s right.
Accordingly, any fish (1) taken in Washington waters or in United States waters off the coast of Washington, (2) taken from runs of fish that pass through the Indians' usual and accustomed fishing grounds, and (3) taken by either members of the Indian tribes that are parties to this litigation, on the one hand, or by non-Indian citizens of Washington, on the other hand, shall count against that party’s respective share of the fish.
VI
Regardless of the Indians’ other fishing rights under -the treaties, the State argues that an agreement between Canada and the United States pre-empts their rights with respect to the sockeye and pink salmon runs on the Fraser River.
In 1930, the United States and Canada agreed that the catch of Fraser River salmon should be equally divided between Canadian and American fishermen. Convention of May 26, 1930, 50 Stat. 1355, as amended by [1957] 8 U. S. T. 1058. To implement this agreement, the two Governments established the International Pacific Salmon Fisheries Commission (IPSFC). Each year that Commission proposes regulations to govern the time, manner, and number of the catch by the fishermen of the two countries; those regulations become.effective upon approval of both countries.
In the United States, pursuant to statute and Presidential designation, enforcement of those regulations is vested in the National Marine Fisheries Service, which-, in turn, may authorize the State of Washington to act as the enforcing agent. Sockeye Salmon or Pink Salmon Fishing Act of 1947, 61 Stat. 511, as amended, 16 U. S. C. § 776 et seq. (hereinafter Sockeye Act). For many years Washington has accepted this responsibility and enacted IPSFC regulations into state statutory law.
The Fraser River salmon run passes through certain “usual and accustomed” places of treaty tribes. The Indians have therefore claimed a share of these runs. Consistently with its basic interpretation of the Indian treaties, the District Court in its original decision held that the tribes are entitled to up to one-half of the American share of any run that passes through their “usual and accustomed” places. To implement that holding, the District Court also entered an order authorizing the use by Indians of certain gear prohibited by IPSFC regulations then in force. 384 F. Supp., at 392-393, 411. The Court of Appeals affirmed, 520 F. 2d, at 689-690, and we denied certiorari. 423 U. S. 1086.
In later proceedings commenced in 1975, the State of Washington contended in the District Court that any Indian rights to Fraser River salmon were extinguished either implicitly by the later agreement with Canada or more directly by the IPSFC regulations promulgated pursuant to those agreements insofar as they are inconsistent with the District Court’s order. The State’s claim was rejected by the District Court and the Court of Appeals. 459 F. Supp., at 1050-1056; 573 F. 2d, at 1120-1121.
First, we agree with the Court of Appeals that the Convention itself does not implicitly extinguish the Indians’ treaty rights. Absent explicit statutory language, we have been extremely reluctant to find congressional abrogation of treaty rights, e. g., Menominee Tribe v. United States, 391 U. S. 404, and there is no reason to do so here. Indeed, the Canadian Government has long exempted Canadian Indians from regulations promulgated under the Convention and afforded them special fishing rights.
We also agree with the United States that the conflict between the District Court’s order and IPSFC does not present us with a justiciable issue. The initial conflict occasioned by the regulations for the 1975 season has been mooted by the passage of time, and there is little prospect that a similar conflict will revive and yet evade review. See DeFunis v. Odegaard, 416 U. S. 312, 316. Since 1975, the United States, in order to protect the Indian rights, has exercised its power under Art. VI of the Convention and refused to give the necessary approval to those portions of the IPSFC regulations that affected Indian fishing rights. Those regulations have accordingly not gone into effect in the United States. The Indians’ fishing rights and responsibilities have instead been the subject of separate regulations promulgated by.the Interior Department, under its general Indian powers, 25 U. S. C. §§ 2, 9; see 25 CFR § 256.11 et seq. (1978); 50 CFR § 371.1 et seq. (1978); 25 CFR § 256.11 et seq. (1979), and enforced by the National Marine Fisheries Service directly, rather than by delegation to the State. The District Court’s order is fully consistent with those regulations. To the extent that any Washington State statute imposes any conflicting obligations, the statute is without effect under the Sockeye Act and must give way to the federal treaties, regulations, and decrees. E. g., Missouri v. Holland, 252 U. S. 416, 432.
VII
In addition to their challenges to the District Court’s basic construction of the treaties, and to the scope of its allocation of fish to treaty fishermen, the State and the commercial fishing associations have advanced two objections to various remedial orders entered by the District Court. It is claimed that the District Court has ordered a state agency to take action that it has no authority to take as a matter of state law and that its own assumption of the authority to manage the fisheries in the State after the state agencies refused or were unable to do so was unlawful.
These objections are difficult to evaluate in view of the representations to this Court by the Attorney General of the State that definitive resolution of the basic federal question of construction of the treaties will both remove any state-law impediment to enforcement of the State’s obligations under the treaties, and enable the State and Fisheries to carry out those obligations. Once the state agencies comply, of course, there would be no issue relating to federal authority to order them to do so or any need for the District Court to continue its own direct supervision of enforcement efforts.
The representations of the Attorney General are not binding on the courts and legislature of the State, although we assume they are authoritative within its executive branch. Moreover, the State continues to argue that the District Court exceeded its authority when it assumed control of the fisheries in the State, and the commercial fishing groups continue to argue that the District Court may not order the state agencies to comply with its orders when they have no state-law authority to do so. Accordingly, although adherence to the Attorney General’s representations by the executive, legislative, and judicial officials in the State would moot these two issues, a brief discussion should foreclose the possibility that they will not be respected. State-law prohibition against compliance with the District Court’s decree cannot survive the command of the Supremacy Clause of the United States Constitution. Cooper v. Aaron, 358 U. S. 1; Ableman v. Booth, 21 How. 506. It is also clear that Game and Fisheries, as parties to this litigation, may be ordered to prepare a set of rules that will implement the Court’s interpretation of the rights of the parties even if state law withholds from them the power to do so. E. g., North Carolina Board of Education v. Swann, 402 U. S. 43; Griffin v. County School Board, 377 U. S. 218; Tacoma v. Taxpayers, 357 U. S. 320. Once again the answer to a question raised by this litigation is largely dictated by our Puyallup trilogy. There, this Court mandated that state officers make precisely the same type of allocation of fish as the District Court ordered in this case. See Puyallup III, 433 U. S., at 177.
Whether Game and Fisheries may be ordered actually to promulgate regulations having effect as a matter of state law may well be doubtful. But the District Court may prescind that problem by assuming direct supervision of the fisheries if state recalcitrance or state-law barriers should be continued. It is therefore absurd to argue, as do the fishing associations, both that the state agencies may not be ordered to implement the decree and also that the District Court may not itself issue detailed remedial orders as a substitute for state supervision. The federal court unquestionably has the power to enter the various orders that state official and private parties have chosen to ignore, and even to displace local enforcement of those orders if necessary to remedy the violations of federal law found by the court. E. g., Hutto v. Finney, 437 U. S. 678; Milliken v. Bradley, 433 U. S. 267, 280-281, 290; Swann v. Charlotte-Mecklenburg Board of Education, 402 U. S. 1, 15. Even if those orders may have been erroneous in some respects, all parties have an unequivocal obligation to obey them while they remain in effect.
In short, we trust that the spirit of cooperation motivating the Attorney General’s representation will be confirmed by the conduct of state officials. But if it is not, the District Court has the power to undertake the necessary remedial steps and to enlist the aid of the appropriate federal law enforcement agents in carrying out those steps. Moreover, the comments by the Court of Appeals strongly imply that it is prepared to uphold the use of stern measures to require respect for federal-court orders.
The judgments of the Court of Appeals for the Ninth Circuit and the Supreme Court of the State of Washington are vacated and the respective causes are remanded to those courts for further proceedings not inconsistent with this opinion, except that the judgment in United States v. Washington, 573 F. 2d 1118 (the International Fisheries case) is affirmed.
So ordered.
By three earlier treaties the United States had extinguished the conflicting claims of Spain in 1820 and Russia in 1824, 8 Stat. 252, 302, and Great Britain in 1846, 9 Stat. 869. In 1848, Congress established the Oregon Territory, 9 Stat. 323; that statute provided that nothing contained therein “shall be construed to impair the rights of person or property now pertaining to the Indians and said Territory, so long as such rights shall remain unextinguished by treaty between the United States and such Indians.” In 1850, Congress authorized the negotiation of treaties to extinguish the Indian claims to land lying west of the Cascade Mountains, 9 Stat. 437. In 1853, the Washington Territory, which includes the present State of Washington, was organized out of the Oregon Territory. Ch. 90, 10 Stat. 172.
Treaty of Medicine Creek (10 Stat. 1132); Treaty of Point Elliott (12 Stat. 927); Treaty of Point No Point (12 Stat. 933); Treaty of Neah Bay (12 Stat. 939); 'Treaty with the Yakamas (12 Stat. 951); and Treaty of Olympia (12 Stat. 971). The parties to the treaties and to this litigation include these Indian tribes: Hoh; Lower Elwha Band of Clallam Indians; Lummi; Makah; Muckleshoot; Nisqually; Nooksack; Port Gamble Band of Clallam Indians; Puyallup; Quileute; Quinault; Sauk-Suiattle; Skokomish; Squaxin Island; Stillaguamish; Suquamish; Swinomish; Tulalip; Upper Skagit; and Yakima Nation. 384 F. Supp. 312, 349; 459 F. Supp. 1020, 1028.
For example, pink and soekeye salmon hatched in Canada’s Fraser River pass through the Strait of Juan de Fuca in the State of Washington, swim out into international waters on the open sea, and return through the strait to the river, passing on the way the usual and accustomed fishing grounds of the Makah Indian Tribe once again in Washington. 384 F. Supp., at 392. During much of the return run during which they pass through international, state, and Canadian waters, the fish are in optimum harvestable condition. See also id., at 386-387, regarding the Puget Sound and Olympic Peninsula origin chinook salmon that pass through international waters, as well as those of Washington, Canada, and Alaska.
Although in terms of the number and weight of the fish involved, the commercial salmon catch is far more substantial than the recreational steelhead catch, the latter apparently provides the State with more revenue than the former, involves more people, and has accordingly been a more controversial political issue within the State. See id,., at 399.
Indeed, the record shows that the territorial officials who negotiated the treaties on behalf of the United States took the initiative in aggregating certain loose bands into designated tribes and even appointed many of the chiefs who signed the treaties. Id., at 354-355, 366.
“From the earliest known times, up to and beyond the time of the . . . treaties, the Indians comprising each of the treating tribes and bands were primarily a fishing, hunting and gathering people dependent almost entirely upon the natural animal and vegetative resources of the region for their subsistence and culture. They were heavily dependent upon anadromous fish for their subsistence and for trade with other tribes and later with the settlers. Anadromous fish was the great staple of their diet and livelihood. They cured and dried large quantities for year around use, both for themselves and for others through sale, trade, barter and employment.” Id., at 406. See also 520 F. 2d 676, 682 (“The Indians west of the Cascade Mountains were known as 'fish-eaters’; their diets, social customs, and religious practices centered on the capture of fish”).
“At the time of the treaties, trade was carried on among the Indian groups throughout a wide geographic area. Fish was a basic element of the trade. There is some evidence that the volume of this intra-tribal trade was substantial, but it is not possible to compare it with the volume of present day commercial trading in salmon. Such trading was, however, important to the Indians at the time of the treaties. In addition to potlatching, which is a system of exchange between communities in a social context often typified by competitive gifting, there was a considerable amount of outright sale and trade beyond the local community and sometimes over great distances. In the decade immediately preceding the treaties, Indian fishing increased in order to accommodate increased demand for local non-Indian consumption and for export, as well as to provide money for purchase of introduced commodities and to obtain substitute non-Indian goods for native products which were no longer available because of the non-Indian movement into the area. Those involved in negotiating the treaties recognized the contribution that Indian fishermen made to the territorial economy because Indians caught most of the non-Indians’ fish for them, plus clams and oysters.” 384 F. Supp., at 351-352 (citations to record omitted). See also id., at 364 (Makah Tribe “maintained from time immemorial a thriving economy based on commerce” in “marine resources”).
In late December 1854, one territorial official wrote the Commissioner of Indian Affairs that “[t]he Indians on Puget Sound . . . form a very considerable portion of the trade of the Sound. . . . They catch most of our fish, supplying not only our people with clams and oysters, but salmon to those who cure and export it.” App. 329.
Governor Stevens in discussing the policy that he intended to pursue during negotiations with the tribes, in a letter dated September 16, 1854, to the Commissioner of Indian Affairs, said:
“The subject of the right of fisheries is one upon which legislation is demanded. It never could have been the intention of Congress that Indians should be excluded from their ancient fisheries; but, as no condition to this effect was inserted in the donation act, the question has been raised whether persons taking claims, including such fisheries, do not possess the right of monopolizing. It is therefore desirable that this question should be set at rest by law.” Id., at 327. See also id., at 332.
The Governor’s concern with protecting the Indians’ continued exploitation of their accustomed fisheries was reflected in his assurances to the Indians during the treaty negotiations that under the treaties they would be able to go outside of reservation areas for the purpose of harvesting fish. His statement at the signing of the Treaty of Point Elliott on Monday, January 22, 1855, was characteristic:
“We want to place you in homes where you can cultivate the soil, using potatoes and other articles of food, and where you will be able to pass in canoes over the waters of the Sound and catch fish and back to the mountains to get roots and berries.” Id., at 329-330.
Indeed, the translation of the English words was difficult because the interpreter used a “Chinook jargon” to explain treaty terms, and that jargon not only was imperfectly (and often not) understood by many of the Indians but also was composed of a simple 300-word commercial vocabulary that did not include words corresponding to many of the treaty terms. 384 F. Supp., at 330, 355-356, 364, 381; 520 F. 2d, at 683.
For example, Governor Stevens made the following statement to the Indians gathered at Point-No-Point to negotiate the treaty bearing that name:
“Are you not my children and also children of the Great Father? What will I not do for my children, and what will you not for yours? Would you not die for them? This paper is such as a man would give to his children and I will tell you why. This paper gives you a home. Does not a father give his children a home? . . . This paper secures your fish? Does not a father give food to his children?” App. 330-331.
“There is nothing in the written records of the treaty councils or other accounts of discussions with the Indians to indicate that the Indians were told that their existing fishing activities or tribal control over them would in any way be restricted or impaired by the treaty. The most that could be implied from the treaty context is that the Indians may have been told or understood that non-Indians would be allowed to take fish at the Indian fishing locations along with the Indians.” 384 F. Supp., at 357.
“The non-Indian commercial fishing industry did not fully develop in the ease area until after the invention and perfection of the canning process. The first salmon cannery in Puget Sound began in 1877 with a small operation at Mukilteo. Large-scale development of the commercial fisheries did not commence in Puget Sound until the mid-1890’s. The large-scale development of the commercial fishing industry in the last decades of the Nineteenth Century brought about the need for regulation of fish harvests.” Id., at 352 (record citations omitted). See also id., at 406.
The impact of illegal regulation, see Tulee v. Washington, 315 U. S. 681, and of illegal exclusionary tactics by non-Indians, see United States v. Winans, 198 U. S. 371, in large measure accounts for the decline of the Indian fisheries during this century and renders that decline irrelevant to a determination of the fishing rights the Indians assumed they were securing by initialing the treaties in the middle of the last century.
The “harvestable” amount of fish is determined by subtracting from the total number of fish in each run the number that must be allowed to escape for conservation purposes.
The “ease area” was defined by the District Court as
“that portion of the State of Washington west of the Cascade Mountains and north of the Columbia River drainage area, and includes the American portion of the Puget Sound watershed, the watersheds of the Olympic Peninsula north of the Grays Harbor watershed, and the offshore waters adjacent to those areas.” 384 F. Supp., at 328.
A factual dispute exists on the question of what percentage of the fish in the ease area actually passes through Indian fishing areas and is therefore subject to the District Court’s allocations. In the absence of any relevant findings by the courts below, we are unable to express any view on the matter.
Moreover, fish caught by individual Indians at off-reservation locations that are not “usual and accustomed” sites, were treated as if they had been caught by nontreaty fishermen. 384 F. Supp., at 410.
The Court of Appeals held that fish caught by nonresidents of Washington should be eliminated from the equitable adjustment for fish caught beyond the State’s jurisdiction. 520 F. 2d, at 689.
Despite our earlier denial of certiorari on the treaty interpretation issue, we decline the Government’s invitation to treat the matter as having been finally adjudicated. Our earlier denial came at an interlocutory stage in the proceedings — the District Court has retained continuing enforcement jurisdiction over the case — so that we certainly are not required to treat the earlier disposition as final for our purposes. Reece v. Georgia, 350 U. S. 85, 87. Moreover, the reason for our recent grant of certiorari on the question remains because the state courts are — and, at least since the State Supreme Court’s decision in Department of Game v. Puyallup Tribe, 86 Wash. 2d 664, 548 P. 2d 1058 (1976), have been — on record as interpreting the treaties involved differently from the federal courts. Accordingly, there is strong reason not to treat it as final as a discretionary matter.
The Washington Supreme Court held that the treaties would violate equal protection principles if they provided fishing rights to Indians that were not also available to non-Indians. The simplest answer to this argument is that this Court has already held that these treaties confer enforceable special benefits on signatory Indian tribes, e. g., Tulee v. Washington, 315 U. S. 681; United States v. Winans, 198 U. S. 317, and has repeatedly held that the peculiar semisovereign and constitutionally recognized status of Indians justifies special treatment on their behalf when rationally related to the Government’s “unique obligation toward the Indians.” Morton v. Mancari, 417 U. S. 535, 555. See United States v. Antelope, 430 U. S. 641; Antoine v. Washington, 420 U. S. 194. See also Fishing Vessel Assn. v. Tollefson, 89 Wash. 2d 276, 287-288, 571 P. 2d 1373, 1379-1380 (1977) (Utter, J., dissenting).
The language is quoted from Art. Ill of the Treaty of Medicine Creek, 10 Stat. 1133. Identical, or almost identical, language is included in each of the other treaties.
The State characterizes its interpretation of the treaty language as assuring Indians and non-Indians an “equal opportunity” to take fish from the State’s waters. This appellation is misleading. In the first place, even the State recognizes that the treaties provide Indians with certain rights — i. e., the right to fish without a license and to cross private lands — that non-Indians do not have. See Tulee v. Washington, 315 U. S. 681; Seufert Bros. Co. v. United States, 249 U. S. 194; United States v. Winans, 198 U. S. 371. See also Puyallup Tribe v. Washington Game Dept., 433 U. S. 165. Whatever opportunities the treaties assure Indians with respect to fish are admittedly not “equal” to, but are to some extent greater than, those afforded other citizens. It is therefore simply erroneous to suggest that the treaty language “confers upon non-Indians precisely the same right to fish that it confers upon Indians.” Powell, J., dissenting, post, at 698.
Moreover, in light of the far superior numbers, capital resources, and technology of the non-Indians, the concept of the Indians’ “equal opportunity” to take advantage of a scarce resource is likely in practice to mean that the Indians’ “right of taking fish” will net them virtually no catch at all. For the “opportunity” is at best theoretical. Indeed, in 1974, before the District Court’s injunction took effect, and while the Indians were still operating under the “equal opportunity” doctrine, their take amounted to approximately 2% of the total harvest of salmon and trout in the treaty area. 459 F. Supp., at 1032.
The State argues that at common law a “common fishery” was merely a nonexclusive right of access, see 3 J. Kent, Commentaries 412 . (5th ed. 1844), and that the right of a fishery was appurtenant to specific parcels of real property. The State does not suggest, however, that these concepts were understood by, or explained to, the Indians. Indeed, there is no evidence that Governor Stevens understood them, although one of his advisers, George Gibbs, was a lawyer.
But even if we indulge in the highly dubious assumption that Gibbs was learned in the intricacies of water law, that he incorporated them in the treaties, and that he explained them fully to the Indians, the treaty language would still be subject to the different interpretations presented by the parties to this litigation. For in addition to “common fisheries,” the “in common with” language was used in two other relevant senses during the period. First, a “common of fishery” meant a limited right, acquired from the previously exclusive owner of certain fishing rights (in this case the Indians), “of taking fish in common with certain others in waters flowing through [the grantor’s] land.” J. Gould, Laws of Waters § 183 (3d ed. 1900) (emphasis added); see 3 Kent, swpra, at 410. Under that understanding of the language, it would hardly make sense that the Indians effectively relinquished all of their fishing rights by granting a merely nonexclusive right.
Even more to the point, the United States had previously used the “in common with” language in two treaties with Britain, including one signed in 1854, that dealt with fishing rights in certain waters adjoining the United States and Canada. Treaty of Oct. 20, 1818, 8 Stat. 248; Treaty of June 5, 1854, 10 Stat. 1089. As interpreted by the Department of State during the 19th century, these treaties gave each signatory country an “equal” and apportionable “share” of the take of fish in the treaty areas. See H. R. Ex. Doc. No. 84, 46th Cong., 2d Sess., 7 (1880); 5 American State Papers (For. Rel.) 528-529 (1823); J. Q. Adams, The Duplicate Letters, The Fisheries and the Mississippi 184H85 (1822).
Puyallwp Tribe v. Washington Game Dept., 391 U. S. 392 (Puyallup I); Washington Game Dept. v. Puyallup Tribe, 414 U. S. 44 (Puyallup II); and Puyallup Tribe v. Washington Game Dept., 433 U. S. 165 (Puyallup III).
Mr. Justice Douglas wrote for the Court:
“The right to fish 'at all usual and accustomed’ places may, of course, not be qualified by the State .... But the manner of fishing, the size of the take, the restriction of commercial fishing, and the like may be regulated by the State in the interest of conservation, provided the regulation meets appropriate standards and does not discriminate against the Indians.” 391 U. S., at 398.
In describing the “appropriate standards” referred to, Mr. Justice Douglas continued:
“As to a ‘regulation’ concerning the time and manner of fishing . . . , the power of the State [is] measured by whether [the regulation is] ‘necessary for the conservation of fish.’ [Tulee¡\ 315 II. S., at 684.
“The measure of the legal propriety of those kinds of conservation measures is therefore distinct from the federal constitutional standard concerning the scope of the police power of a State. See Ferguson v. Skrupa, 372 II. S. 726 .. . .” Id., at 402 n. 14.
See also Antoine v. Washington, 420 U. S., at 207-208; Tulee, 315 U. S., at 684; Winans, 198 U. S., at 384; Ward v. Race Horse, 163 U. S. 504.
Although some members of the Washington Supreme Court in their opinions in Puyallup III expressed the view that the treaties could not be interpreted as affording treaty fishermen an allocable share of the fish, Department of Game v. Puyallup Tribe, 86 Wash. 2d, at 674-681, 548 P. 2d, at 1066-1070; see id., at 690-698, 548 P. 2d, at 1075-1080 (Rosellini, J., concurring); but see id., at 688-690, 548 P. 2d, at 1074-1075 (Stafford, C. J., concurring in result), they recognized that any other interpretation would be inconsistent with “the express language on the face of [this Court’s decision in] Puyallup II . . . .”
Because the 50% figure is only a ceiling, it is not correct to characterize our holding “as guaranteeing the Indians a specified percentage” of the fish. See Powell, J., dissenting, post, at 697.
The logic of the 50% ceiling is manifest. For an equal division— especially between parties who presumptively treated with each other as equals — is suggested, if not necessarily dictated, by the word “common” as it appears in the treaties. Since the days of Solomon, such a division has been accepted as a fair apportionment of a common asset, and Anglo-American common law has presumed that division when, as here, no other percentage is suggested by the language of the agreement or the surrounding circumstances. E. g., 2 American Law of Property § 6.5, p. 19 (A. Casner ed. 1952); E. Hopkins, Handbook on the Law of Real Property § 209, p. 336 (1896).
This Court’s decision in Puyallup III, which approved state regulation of on-reservation fishing in the interest of conservation, was issued after the District Court excluded the Indians’ on-reservation take and the Court of Appeals affirmed. See 520 F. 2d, at 690.
A like reasoning requires the fish taken by treaty fishermen off the reservations and at locations other than “usual and accustomed” sites, see n. 17, supra, to be counted as part of the Indians’ share. Of course, the District Court, in its discretion, may determine that so few fish fit into this, or any other, category (e. g., “take-home” fish caught by nontreaty commercial fishermen for personal use) that accounting for them individually is unnecessary, and that an estimated figure may be relied on in making the annual computation. Indeed, if the amount is truly de minimis, no accounting at all may be required.
The Government suggests that the District Court's exclusion of the "take-home” catch of nontreaty fishermen from the nontreaty share makes up for any losses to those fishermen occasioned by the exclusion of the Indians' ceremonial and subsistence take. We see nothing in the District Court’s findings to verify this allegation, see 384 F. Supp., at 343, although the District Court may wish to address the issue in this light on remand.
Although there is some discussion in the briefs concerning whether the treaties give Indians the same right to take hatchery-bred fish as they do to take native fish, the District Court has not yet reached a final decision on this issue, see 459 F. Supp., at 1072-1085, and it is not therefore fairly subsumed within our grant of certiorari. See Puyallup III, 433 U. S., at 177 n. 17.
Although the IPSFC has refused to accede to the suggestions of the United States that special regulations be promulgated to cover the Indian fisheries, we are informed by the Solicitor General that the Canadian Government has no objection to those suggestions, has unilaterally implemented similar rules on behalf of its own Indians, and has expressed no dissatisfaction with the unilateral actions taken by the United States in this regard. Brief for United States 40 n. 26.
Because the Department of the Interior regulations assure that no disproportion will occur, the equitable adjustment ordered by the District Court to cover the possibility that IPSFC regulations would result in a disproportionate nontreaty take will not be effectuated. We accordingly have no issue before us concerning the validity of that adjustment.
The associations advance a third objection as well — that the District Court had no power to enjoin individual nontreaty fishermen, who were not parties, to its decisions, from violating the allocations that it has ordered. The reason this issue has arisen is that state officials were either unwilling or unable to enforce the District Court’s orders against nontreaty fishermen by way of state regulations and state law enforcement efforts. Accordingly, nontreaty fishermen were openly violating Indian fishing rights, and, in order to give federal law enforcement officials the power via contempt to end those violations, the District Court was forced to enjoin them. 459 F. Supp., at 1043, 1098-1099, 1113-1117. The commercial fishing organizations, on behalf of their individual members, argue that they should not be bound by these orders because they were not parties to (although the associations all did participate as amici curiae in) the proceedings that led to their issuance.
If all state officials stand by the Attorney General’s representations that the State will implement the decision of this Court, see nn. 34 and 35, infra, this issue will be rendered moot because the District Court no longer will be forced to enforce its own decisions. Nonetheless, the issue is still live since state implementation efforts are now at a standstill and the orders are still in effect. Accordingly, we must decide it.
In our view, the commercial fishing associations and their members are probably subject to injunction under either the rule that nonparties who interfere with the implementation of court orders establishing public rights may be enjoined, e. g., United States v. Hall, 472 F. 2d 261 (CA5 1972), cited approvingly in Golden State Bottling Co. v. NLRB, 414 U. S. 168, 180, or the rule that a court possessed of the res in a proceeding in rem, such as one to apportion a fishery, may enjoin those who would interfere with that custody. See Vendo Co. v. Lektro-Vend Corp., 433 U. S. 623, 641. But in any case, these individuals and groups are citizens of the State of Washington, which was a party to the relevant proceedings, and “they, in their common public rights as citizens of the State, were represented by the State in those proceedings, and, like it, were bound by the judgment.” Tacoma v. Taxpayers, 357 U. S. 320, 340-341. Moreover, a court clearly may order them to obey that judgment. See Golden State Bottling, supra, at 179-180.
The State has also argued that absent congressional legislation the treaties involved here are not enforceable. This argument flies directly in the face of Art. XIII of the treaties which states that they “shall be obligatory on the contracting parties as soon as [they are] ratified by the President and Senate of the United States.” Moreover, the argument was implicitly rejected in Winans and our ensuing decisions regarding these treaties, all of which assumed that the treaties are self-enforcing. E. g., Puyallup I, 391 U. S., at 397-398.
Significantly, Congress thrice rejected efforts in the early 1960’s to terminate the Indians' fishing rights under these treaties. See S. J. Res. 170 and 171, 88th Cong., 2d Sess. (1964); H. J. Res. 48, 88th Cong., 1st Sess. (1963); H. J. Res. 698, 87th Cong., 2d Sess. (1962).
In his brief, the Attorney General represented:
“If this Court now concludes that Indian treaty fishermen and all other fishermen are not members of the same class with respect to an allocation of fishery, it will thereby lay the foundation for the validity under state law of a separate classification of treaty Indian fishermen for the purpose of allocation. We would respectfully submit that if the Court rejects our earlier argument and finds that treaty Indian fishermen are a special class for allocation purposes, such a conclusion would remove the impediment found by the Washington Supreme Court to the exercise of necessary regulatory power by the Department of Fisheries to allocate between Indian and non-Indian fishermen.
“Fisheries will be able to comply with the Court's decision in this case even if it requires some type of allocation of the fishery.” Brief for State of Washington 99.
See also Department of Game v. Puyallup Tribe, 86 Wash. 2d 664, 681, 684-688, 548 P. 2d 1058, 1070, 1072-1074 (1976), in which the Washington Supreme Court held that the Department of Game had authority to allocate a certain portion of the steelhead trout run on the Puyallup River to treaty fishermen.
According to the Attorney General:
“The State of Washington and its Department of Fisheries cannot emphasize too strongly that they .do not propose to inhibit the enforcement of proper federal court orders. . . .
“Whatever the decision of this Court, the state will implement it. The state believes that after a decision by this Court it will be in a position to comply with District Court orders, if the same are necessary to comply with this Court’s decision. We do not believe the state courts could or would take a different point of view: We are confident that they will accede to this Court’s interpretation of the treaties in the future just as they have in the past, as this Court expressly found in Puyallup III, [433 U. S.,] at 177.” Brief for State of Washington 95, 96.
We note the omission of the same firm representation on behalf of the Game Department. Although the history of that agency is not nearly as favorable as that of Fisheries with respect to attempting to comply with the District Court’s order, e. g., 384 F. Supp., at 395, 398; 459 F. Supp., at 1043, 1045, 1099, we assume that this omission stems from the fact that only Fisheries was named as a party in the litigation in the state courts regarding the state agencies’ authority to comply with the District Court’s order. See 88 Wash. 2d, at 679, 565 P. 2d, at 1152. See also Department of Game v. Puyallup Tribe, discussed in n. 34, supra.
“The state’s extraordinary machinations in resisting the [1974] decree have forced the district court to take over a large share of the management of the state’s fishery in order to enforce its decrees. Except for some desegregation cases . . . , the district court has faced the most concerted official and private efforts to frustrate a decree of a federal court witnessed in this century. The challenged orders in this appeal must be reviewed by this court in the context of events forced by litigants who offered the court no reasonable choice.” 573 E. 2d 1123, 1126 (CA9 1978).