Mr. Justice Blackmun
delivered the opinion of the Court.
Mississippi, prompted by the pendency of private title litigation in the Arkansas courts, instituted this original action against Arkansas in November 1970. The bill of complaint, which accompanied the motion for leave to file, prayed that the boundary line between the two States, in the old bed of the Mississippi River from the upstream end to the downstream end of Tarpley Cut-off, that is, the Spanish Moss Bend-Luna Bar-Carter Point area where Arkansas’ Chicot County and Mississippi’s Washington County adjoin, be fixed and determined.
The river was originally established as the boundary between the States by their respective Acts of Admission. Mississippi’s Act, 3 Stat. 348 (1817), described the line as “up” the river. Arkansas’ Act, 5 Stat. 50 (1836), described the line as “up the middle of the main channel of the said river.” See, also, Arkansas’ Constitution, Art. 1 (1874). Over 50 years ago the question whether there was any difference in the meaning' of these two descriptions was resolved and the boundary was determined to be “the middle of the main navigable channel, and not along the line equidistant between the banks.” Arkansas v. Mississippi, 250 U. S. 39, 43 (1919). That decision was in conformity with the rule of the thalweg enunciated in Iowa v. Illinois,, 147 U. S. 1, 7-8, 13 (1893), and followed, in the absence of special circumstances, in many subsequent cases. See, for example, Minnesota v. Wisconsin, 252 U. S. 273, 281-282 (1920); New Jersey v. Delaware, 291 U. S. 361, 379-380 (1934); Arkansas v. Tennessee, 310 U. S. 563, 571 (1940).
Arkansas responded to Mississippi’s motion and moved that leave to file be denied and that the complaint be dismissed. The motion for leave to file, however, was granted. 400 U. S. 1019 (1971). Thereafter, the Honorable Clifford O’Sullivan was appointed Special Master. 402 U. S. 926 (1971). The Master’s report eventually issued and was ordered filed. 411 U. S. 913 (1973). Arkansas’ exceptions to the report and Mississippi’s response to those exceptions were forthcoming in due course and the case has been argued to this Court.
Prior to 1935 Spanish Moss Bend was on the thalweg, or primary channel, of the Mississippi River. It has not been the thalweg, however, since the Tarpley Cut-off was established about five miles to the east in 1935 by the United States Army Corps of Engineers. The present controversy focuses on what is known as Luna Bar on the eastern bank of the old river at Spanish Moss Bend. The issue simply is whether Luna Bar came into being by gradual migration of the river westward, or, instead, by some avulsive process, also to the westward. Depending on the resolution of this factual issue, legal consequences ensue in line with established principles conceded by the two States to be the law relating to riparian accretion and avulsion. Nebraska v. Iowa, 143 U. S. 359 (1892); Missouri v. Nebraska, 196 U. S. 23 (1904); Bonelli Cattle Co. v. Arizona, 414 U. S. 313, 325-327 (1973). These principles need no reiteration here. It suffices to say that if Luna Bar was formed by accretion, this litigation is to be resolved in favor of Mississippi, and, contrarily, if Luna Bar resulted from an avulsion, the suit is to be resolved in favor of Arkansas.
Upon our independent review of the record, we find ourselves in complete agreement and accord with the findings of fact made by the Special Master. Report 34. We therefore affirm those findings, overrule Arkansas’ exceptions to the Master’s report, confirm that report, and in general accept the Master’s recommendations for a decree.
We deem it unnecessary to outline at length the evidence adduced, or to reproduce here the detailed analysis of that evidence made by the Special Master. We note only that the dissent would regard the case as close because of three factors: (1) certain testimony as to ancient trees on Luna Bar indicated by the presence of three stumps that could not have lived and died there in the last 100 years, (2) some testimony as to soil on the bar “not compatible with the soil that would result from accretion,” post, at 298, and (3) the bar’s “hard core . . . elevation,” post, at 299-300, that coincides with the elevation “on the adjacent Arkansas bank.” These factors, in our view, would be pertinent except that they reflect only the approach and testimony of Arkansas’ witnesses and overlook pertinent and persuasive testimony to the opposite effect from expert witnesses for Mississippi. The latter are the witnesses that the Special Master credited, as do we, in the evaluation of the conflicting testimony.
Arkansas conceded that Mississippi made out a prima facie case of accretion. Tr. of Oral Arg. 19. In addition, the Master was impressed with the total absence of any known historical reference to an avulsion in this area that changed the course of the river by the necessary half mile. And the dissent acknowledges, post, at 295, as to how “Mississippi made its case,” and concedes that the testimony “gives force to the argument that accretion formed Luna Bar,” that there was testimony that in the Mississippi River “avulsion would shorten the course of the river, while here the course was lengthened,” and that Mississippi's experts knew of no instance “where avulsion had worked the way Arkansas claims.”
So far as the ancient tree stumps are concerned, Mississippi presented evidence from forestry experts that the forest on Luna Bar was one predominantly of pioneer species with the expected small accompanying, scattered areas of secondary and climax trees, and with no tree more than 37 years old. This is consistent with the first appearance of growth upon Luna Bar depicted in early Mississippi River Commission charts showing the bar to be barren and without vegetation. Report 10. Mississippi's position as to the three particular stumps was that they had been washed in by floodwaters in preceding years; that one had moss on its roots, a condition incompatible with growth in place; and that, at the point where another allegedly was found in 1972, the elevation of the bar was at least 10 feet above what it had been 90 years earlier. Thus the stump necessarily should have been deep in the undersoil of the bar and not on its surface at the time of its removal. Report 11.
The soil composition is purely a matter of conflicting testimony and we are persuaded by Mississippi's evidence. Deep borings, of course, would be below the riverbed, and would be expected to be consistent throughout the area on both sides of the river. And, as noted above, charts of 1882 and 1894, admitted into evidence, show Luna Bar as a dry sandbar with no vegetation.
The claim of similar elevations, too, encounters strong and convincing opposing authority. Dr. Charles R. Kolb, a highly qualified expert for Mississippi, testified that his study disclosed that the Arkansas bank, from the first comparative recordings until fairly recent times, was about 12 feet higher than Luna Bar. Report 15, 19. R. 354-357. And there is an absence of levee formations on Luna Bar, as contrasted with the presence of pre-1860 levees on the Arkansas bank.
We agree with the Special Master’s evaluation of the evidence and conclude, as he did, that Arkansas did not sustain its burden of rebutting Mississippi’s conceded prima facie case, a burden the Arkansas court has described as “considerable.” Pannell v. Earls, 252 Ark. 385, 388, 483 S. W. 2d 440, 442 (1972).
Upon our own consideration and our independent review of the entire record, of the report filed by the Special Master, of the exceptions filed thereto, and of the argument thereon, a decree is accordingly entered.
It is so ordered.
[For decree adopted and entered by the Court, see post, p. 302.]
See Arkansas Land & Cattle Co. v. Anderson-Tully Co., 248 Ark. 495, 452 S. W. 2d 632 (1970), a 4-3 decision of the Supreme Court of Arkansas.
Mississippi's Constitution of 1890, Art. 2, however, reads, “up the middle of the Mississippi river, or thread of the stream.”
Other orders are reported at 402 U. S. 939 (1971) and at 403 U. S. 951 (1971).
Although the precedent is not binding in this original action between the two States, it is not without interest to note that in private litigation Luna Bar has been determined to be in Mississippi. Anderson-Tully Co. v. Walls, 266 F. Supp. 804 (ND Miss. 1967). Another private suit involving the issue is the one mentioned above as pending in the Arkansas state courts. Arkansas Land & Cattle Co. v. Anderson-Tully Co., supra. Further proceedings in that litigation were stayed on February 16, 1971, by the Chancery Court of Chicot County, Arkansas, until final judgment in the present action. Special counsel for the respective States here were counsel for the private parties in the cited federal and state court cases.
attorney general of the United States, or his office specified state board or department of education city, town, township, village, or borough government or governmental unit state commission, board, committee, or authority county government or county governmental unit, except school district court or judicial district state department or agency governmental employee or job applicant female governmental employee or job applicant minority governmental employee or job applicant minority female governmental employee or job applicant not listed among agencies in the first Administrative Action variable retired or former governmental employee U.S. House of Representatives interstate compact judge state legislature, house, or committee local governmental unit other than a county, city, town, township, village, or borough governmental official, or an official of an agency established under an interstate compact state or U.S. supreme court local school district or board of education U.S. Senate U.S. senator foreign nation or instrumentality state or local governmental taxpayer, or executor of the estate of state college or university United States State person accused, indicted, or suspected of crime advertising business or agency agent, fiduciary, trustee, or executor airplane manufacturer, or manufacturer of parts of airplanes airline distributor, importer, or exporter of alcoholic beverages alien, person subject to a denaturalization proceeding, or one whose citizenship is revoked American Medical Association National Railroad Passenger Corp. amusement establishment, or recreational facility arrested person, or pretrial detainee attorney, or person acting as such;includes bar applicant or law student, or law firm or bar association author, copyright holder bank, savings and loan, credit union, investment company bankrupt person or business, or business in reorganization establishment serving liquor by the glass, or package liquor store water transportation, stevedore bookstore, newsstand, printer, bindery, purveyor or distributor of books or magazines brewery, distillery broker, stock exchange, investment or securities firm construction industry bus or motorized passenger transportation vehicle business, corporation buyer, purchaser cable TV car dealer person convicted of crime tangible property, other than real estate, including contraband chemical company child, children, including adopted or illegitimate religious organization, institution, or person private club or facility coal company or coal mine operator computer business or manufacturer, hardware or software consumer, consumer organization creditor, including institution appearing as such; e.g., a finance company person allegedly criminally insane or mentally incompetent to stand trial defendant debtor real estate developer disabled person or disability benefit claimant distributor person subject to selective service, including conscientious objector drug manufacturer druggist, pharmacist, pharmacy employee, or job applicant, including beneficiaries of employer-employee trust agreement, employee health and welfare fund, or multi-employer pension plan electric equipment manufacturer electric or hydroelectric power utility, power cooperative, or gas and electric company eleemosynary institution or person environmental organization employer. If employer's relations with employees are governed by the nature of the employer's business (e.g., railroad, boat), rather than labor law generally, the more specific designation is used in place of Employer. farmer, farm worker, or farm organization father female employee or job applicant female movie, play, pictorial representation, theatrical production, actor, or exhibitor or distributor of fisherman or fishing company food, meat packing, or processing company, stockyard foreign (non-American) nongovernmental entity franchiser franchisee lesbian, gay, bisexual, transexual person or organization person who guarantees another's obligations handicapped individual, or organization of devoted to health organization or person, nursing home, medical clinic or laboratory, chiropractor heir, or beneficiary, or person so claiming to be hospital, medical center husband, or ex-husband involuntarily committed mental patient Indian, including Indian tribe or nation insurance company, or surety inventor, patent assigner, trademark owner or holder investor injured person or legal entity, nonphysically and non-employment related juvenile government contractor holder of a license or permit, or applicant therefor magazine male medical or Medicaid claimant medical supply or manufacturing co. racial or ethnic minority employee or job applicant minority female employee or job applicant manufacturer management, executive officer, or director, of business entity military personnel, or dependent of, including reservist mining company or miner, excluding coal, oil, or pipeline company mother auto manufacturer newspaper, newsletter, journal of opinion, news service radio and television network, except cable tv nonprofit organization or business nonresident nuclear power plant or facility owner, landlord, or claimant to ownership, fee interest, or possession of land as well as chattels shareholders to whom a tender offer is made tender offer oil company, or natural gas producer elderly person, or organization dedicated to the elderly out of state noncriminal defendant political action committee parent or parents parking lot or service patient of a health professional telephone, telecommunications, or telegraph company physician, MD or DO, dentist, or medical society public interest organization physically injured person, including wrongful death, who is not an employee pipe line company package, luggage, container political candidate, activist, committee, party, party member, organization, or elected official indigent, needy, welfare recipient indigent defendant private person prisoner, inmate of penal institution professional organization, business, or person probationer, or parolee protester, demonstrator, picketer or pamphleteer (non-employment related), or non-indigent loiterer public utility publisher, publishing company radio station racial or ethnic minority person or organization protesting racial or ethnic segregation or discrimination racial or ethnic minority student or applicant for admission to an educational institution realtor journalist, columnist, member of the news media resident restaurant, food vendor retarded person, or mental incompetent retired or former employee railroad private school, college, or university seller or vendor shipper, including importer and exporter shopping center, mall spouse, or former spouse stockholder, shareholder, or bondholder retail business or outlet student, or applicant for admission to an educational institution taxpayer or executor of taxpayer's estate, federal only tenant or lessee theater, studio forest products, lumber, or logging company person traveling or wishing to travel abroad, or overseas travel agent trucking company, or motor carrier television station union member unemployed person or unemployment compensation applicant or claimant union, labor organization, or official of veteran voter, prospective voter, elector, or a nonelective official seeking reapportionment or redistricting of legislative districts (POL) wholesale trade wife, or ex-wife witness, or person under subpoena network slave slave-owner bank of the united states timber company u.s. job applicants or employees Army and Air Force Exchange Service Atomic Energy Commission Secretary or administrative unit or personnel of the U.S. Air Force Department or Secretary of Agriculture Alien Property Custodian Secretary or administrative unit or personnel of the U.S. Army Board of Immigration Appeals Bureau of Indian Affairs Bonneville Power Administration Benefits Review Board Civil Aeronautics Board Bureau of the Census Central Intelligence Agency Commodity Futures Trading Commission Department or Secretary of Commerce Comptroller of Currency Consumer Product Safety Commission Civil Rights Commission Civil Service Commission, U.S. Customs Service or Commissioner of Customs Defense Base Closure and REalignment Commission Drug Enforcement Agency Department or Secretary of Defense (and Department or Secretary of War) Department or Secretary of Energy Department or Secretary of the Interior Department of Justice or Attorney General Department or Secretary of State Department or Secretary of Transportation Department or Secretary of Education U.S. Employees' Compensation Commission, or Commissioner Equal Employment Opportunity Commission Environmental Protection Agency or Administrator Federal Aviation Agency or Administration Federal Bureau of Investigation or Director Federal Bureau of Prisons Farm Credit Administration Federal Communications Commission (including a predecessor, Federal Radio Commission) Federal Credit Union Administration Food and Drug Administration Federal Deposit Insurance Corporation Federal Energy Administration Federal Election Commission Federal Energy Regulatory Commission Federal Housing Administration Federal Home Loan Bank Board Federal Labor Relations Authority Federal Maritime Board Federal Maritime Commission Farmers Home Administration Federal Parole Board Federal Power Commission Federal Railroad Administration Federal Reserve Board of Governors Federal Reserve System Federal Savings and Loan Insurance Corporation Federal Trade Commission Federal Works Administration, or Administrator General Accounting Office Comptroller General General Services Administration Department or Secretary of Health, Education and Welfare Department or Secretary of Health and Human Services Department or Secretary of Housing and Urban Development Interstate Commerce Commission Indian Claims Commission Immigration and Naturalization Service, or Director of, or District Director of, or Immigration and Naturalization Enforcement Internal Revenue Service, Collector, Commissioner, or District Director of Information Security Oversight Office Department or Secretary of Labor Loyalty Review Board Legal Services Corporation Merit Systems Protection Board Multistate Tax Commission National Aeronautics and Space Administration Secretary or administrative unit of the U.S. Navy National Credit Union Administration National Endowment for the Arts National Enforcement Commission National Highway Traffic Safety Administration National Labor Relations Board, or regional office or officer National Mediation Board National Railroad Adjustment Board Nuclear Regulatory Commission National Security Agency Office of Economic Opportunity Office of Management and Budget Office of Price Administration, or Price Administrator Office of Personnel Management Occupational Safety and Health Administration Occupational Safety and Health Review Commission Office of Workers' Compensation Programs Patent Office, or Commissioner of, or Board of Appeals of Pay Board (established under the Economic Stabilization Act of 1970) Pension Benefit Guaranty Corporation U.S. Public Health Service Postal Rate Commission Provider Reimbursement Review Board Renegotiation Board Railroad Adjustment Board Railroad Retirement Board Subversive Activities Control Board Small Business Administration Securities and Exchange Commission Social Security Administration or Commissioner Selective Service System Department or Secretary of the Treasury Tennessee Valley Authority United States Forest Service United States Parole Commission Postal Service and Post Office, or Postmaster General, or Postmaster United States Sentencing Commission Veterans' Administration War Production Board Wage Stabilization Board General Land Office of Commissioners Transportation Security Administration Surface Transportation Board U.S. Shipping Board Emergency Fleet Corp. Reconstruction Finance Corp. Department or Secretary of Homeland Security Unidentifiable International Entity