JUSTICE THOMAS
delivered the opinion of the Court.
This case requires us to clarify the relationship between the rights of employees under § 7 of the National Labor Relations Act (NLRA or Act), 49 Stat. 452, as amended, 29 U. S. C. § 157, and the property rights of their employers.
I
This case stems from the efforts of Local 919 of the United Food and Commercial Workers Union, AFL-CIO, to organize employees at a retail store in Newington, Connecticut, owned and operated by petitioner Lechmere, Inc. The store is located in the Lechmere Shopping Plaza, which occupies a roughly rectangular tract measuring approximately 880 feet from north to south and 740 feet from east to west. Lech-mere's store is situated at the Plaza's south end, with the main parking lot to its north. A strip of 13 smaller "satellite stores" not owned by Lechmere runs along the west side of the Plaza, facing the parking lot. To the Plaza's east (where the main entrance is located) runs the Berlin Turnpike, a four-lane divided highway. The parking 1st, however, does not abut the Turnpike; they are separated by a 46-foot-wide grassy strip, broken only by the Plaza's entrance. The parking lot is owned jointly by Lechmere ~nd the developer of the satellite stores. The grassy strip is public property (except for a 4-foot-wide band adjoining the parking lot, which belongs to Lechmere).
The union began its campaign to organize the store's 200 employees, none of whom was represented by a union, in June 1987. After a full-page advertisement in a local newspaper drew little response, nonemployee union organizers entered Lechmere's parking 1~t and began placing handbills on the windshields of cars parked in a corner of the lot used mostly by employees. Lechmere's manager immediately confronted the organizers, informed them that Lechmere prohibited solicitation or handbill distribution of any kind on its property, and asked them to leave. They did so, and Lechmere personnel removed the handbills. The union organizers renewed this handbilling effort in the parking lot on several subsequent occasions; each time they were asked to leave and the handbills were removed. The organizers then relocated to the public grassy strip, from where they attempted to pass out handbills to cars entering the lot during hours (before opening and after closing) when the drivers were assumed to be primarily store employees. For one month, the union organizers returned daily to the grassy strip to picket Lechmere; after that, they picketed intermittently for another six months. They also recorded the license plate numbers of cars parked in the employee parking area; with the cooperation of the Connecticut Department of Motor Vehicles, they thus secured the names and addresses of some 41 nonsupervisory employees (roughly 20% of the store’s total). The union sent four mailings to these employees; it also made some attempts to contact them by phone or home visits. These mailings and visits resulted in one signed union authorization card.
Alleging that Lechmere had violated the NLRA by barring the nonemployee organizers from its property, the union filed an unfair labor practice charge with respondent National Labor Relations Board (Board). Applying the criteria set forth by the Board in Fairmont Hotel Co., 282 N. L. R. B. 139 (1986), an Administrative Law Judge (ALJ) ruled in the union’s favor. Lechmere, Inc., 295 N. L. R. B. 94 (1988). He recommended that Lechmere be ordered, among other things, to cease and desist from barring the union organizers from the parking lot and to post in conspicuous places in the store signs proclaiming in part:
“WE WILL NOT prohibit representatives of Local 919, United Food and Commercial Workers, AFL-CIO (‘the Union’) or any other labor organization, from distributing union literature to our employees in the parking lot adjacent to our store in Newington, Connecticut, nor will we attempt to cause them to be removed from our parking lot for attempting to do so.” Ibid.
The Board affirmed the ALJ’s judgment and adopted the recommended order, applying the analysis set forth in its opinion in Jean Country, 291 N. L. R. B. 11 (1988), which had by then replaced the short-lived Fairmont Hotel approach. 295 N. L. R. B. 92 (1989). A divided panel of the United States Court of Appeals for the First Circuit denied Lech-mere’s petition for review and enforced the Board’s order. 914 F. 2d 313 (1990). This Court granted certiorari, 499 U. S. 918 (1991).
II
A
Section 7 of the NLRA provides in relevant part that “[ejmployees shall have the right to self-organization, to form, join, or assist labor organizations.” 29 U. S. C. § 157. Section 8(a)(1) of the Act, in turn, makes it an unfair labor practice for an employer “to interfere with, restrain, or coerce employees in the exercise of the rights guaranteed in [§7].” 29 U. S. C. § 158(a)(1). By its plain terms, thus, the NLRA confers rights only on employees, not on unions or their nonemployee organizers. In NLRB v. Babcock & Wilcox Co., 351 U. S. 105 (1956), however, we recognized that insofar as the employees’ “right of self-organization depends in some measure on [their] ability... to learn the advantages of self-organization from others,” id., at 113, § 7 of the NLRA may, in certain limited circumstances, restrict an employer’s right to exclude nonemployee union organizers from his property. It is the nature of those circumstances that we explore today.
Babcock arose out of union attempts to organize employees at a factory located on an isolated 100-acre tract. The company had a policy against solicitation and distribution of literature on its property, which it enforced against all groups. About 40% of the company’s employees lived in a town of some 21,000 persons near the factory; the remainder were scattered over a 30-mile radius. Almost all employees drove to work in private cars and parked in a company lot that adjoined the fenced-in plant area. The parking lot could be reached only by a 100-yard-long driveway connecting it to a public highway. This driveway was mostly on company-owned land, except where it crossed a 31-foot-wide public right-of-way adjoining the highway. Union organizers attempted to distribute literature from this right-of-way. The union also secured the names and addresses of some 100 employees (20% of the total) and sent them three mailings. Still other employees were contacted by telephone or home visit.
The union successfully challenged the company’s refusal to allow nonemployee organizers onto its property before the Board. While acknowledging that there were alternative, nontrespassory means whereby the union could communicate with employees, the Board held that contact at the workplace was preferable. The Babcock & Wilcox Co., 109 N. L. R. B. 485, 493-494 (1954). “[T]he right to distribute is not absolute, but must be accommodated to the circumstances. Where it is impossible or unreasonably difficult for a union to distribute organizational literature to employees entirely off of the employer’s premises, distribution on a nonworking area, such as the parking lot and the walkways between the parking lot and the gate, may be warranted.” Id., at 493. Concluding that traffic on the highway made it unsafe for the union organizers to distribute leaflets from the right-of-way and that contacts through the mails, on the streets, at employees’ homes, and over the telephone would be ineffective, the Board ordered the company to allow the organizers to distribute literature on the company’s parking lot and exterior walkways. Id., at 486-487.
The Court of Appeals for the Fifth Circuit refused to enforce the Board’s order, NLRB v. Babcock & Wilcox Co., 222 F. 2d 316 (1955), and this Court affirmed. While recognizing that “the Board has the responsibility of ‘applying the Act’s general prohibitory language in the light of the infinite combinations of events which might be charged as violative of its terms,’” 351 U. S., at 111-112 (quoting NLRB v. Stowe Spinning Co., 336 U. S. 226, 231 (1949)), we explained that the Board had erred by failing to make the critical distinction between the organizing activities of employees (to whom § 7 guarantees the right of self-organization) and nonemploy-ees (to whom §7 applies only derivatively). Thus, while “[n]o restriction may be placed on the employees’ right to discuss self-organization among themselves, unless the employer can demonstrate that a restriction is necessary to maintain production or discipline,” 351 U. S., at 113 (emphasis added) (citing Republic Aviation Corp. v. NLRB, 324 U. S. 793, 803 (1945)), “no such obligation is owed nonem-ployee organizers,” 351 U. S., at 113. As a rule, then, an employer cannot be compelled to allow distribution of union literature by nonemployee organizers on his property. As with many other rules, however, we recognized an exception. Where “the location of a plant and the living quarters of the employees place the employees beyond the reach of reasonable union efforts to communicate with them,” ibid., employers’ property rights may be “required to yield to the extent needed to permit communication of information on the right to organize,” id., at 112.
Although we have not had occasion to apply Babcock’s analysis in the ensuing decades, we have described it in cases arising in related contexts. Two such cases, Central Hardware Co. v. NLRB, 407 U. S. 539 (1972), and Hudgens v. NLRB, 424 U. S. 507 (1976), involved activity by union supporters on employer-owned property. The principal issue in both cases was whether, based upon Food Employees v. Logan Valley Plaza, Inc., 391 U. S. 308 (1968), the First Amendment protected such activities. In both cases we rejected the First Amendment claims, and in Hudgens we made it clear that Logan Valley was overruled. Having decided the cases on constitutional grounds, we remanded them to the Board for consideration of the union supporters’ §7 claims under Babcock. In both cases, we quoted approvingly Babcock’s admonition that accommodation between employees’ § 7 rights and employers’ property rights “must be obtained with as little destruction of one as is consistent with the maintenance of the other,” 351 U. S., at 112. See Central Hardware, supra, at 544; Hudgens, supra, at 521, 522. There is no hint in Hudgens and Central Hardware, however, that our invocation of Babcock’s language of “accommodation” was intended to repudiate or modify Bab-cock’s holding that an employer need not accommodate non-employee organizers unless the employees are otherwise inaccessible. Indeed, in Central Hardware we expressly noted that nonemployee organizers cannot claim even a limited right of access to a nonconsenting employer’s property until “[a]fter the requisite need for access to the employer’s property has been shown.” 407 U. S., at 545.
If there was any question whether Central Hardware and Hudgens changed § 7 law, it should have been laid to rest by Sears, Roebuck & Co. v. Carpenters, 436 U. S. 180 (1978). As in Central Hardware and Hudgens, the substantive § 7 issue in Sears was a subsidiary one; the case’s primary focus was on the circumstances under which the NLRA pre-empts state law. Among other things, we held in Sears that arguable § 7 claims do not pre-empt state trespass law, in large part because the trespasses of nonemployee union organizers are “far more likely to be unprotected than protected,” 436 U. S., at 205; permitting state courts to evaluate such claims, therefore, does not “create an unacceptable risk of interference with conduct which the Board, and a court reviewing the Board’s decision, would find protected,” ibid. This holding was based upon the following interpretation of Babcock:
“While Babcock indicates that an employer may not always bar nonemployee union organizers from his property, his right to do so remains the general rule. To gain access, the union has the burden of showing that no other reasonable means of communicating its organizational message to the employees exists or that the employer’s access rules discriminate against union solicitation. That the burden imposed on the union is a heavy one is evidenced by the fact that the balance struck by the Board and the courts under the Babcock accommodation principle has rarely been in favor of trespassory organizational activity.” 436 U. S., at 205 (emphasis added; footnotes omitted).
We further noted that, in practice, nonemployee organizational trespassing had generally been prohibited except where “unique obstacles” prevented nontrespassory methods of communication with the employees. Id., at 205-206, n. 41.
B
Jean Country, as noted above, represents the Board’s latest attempt to implement the rights guaranteed by §7. It sets forth a three-factor balancing test:
“[I]n all access cases our essential concern will be [1] the degree of impairment of the Section 7 right if access should be denied, as it balances against [2] the degree of impairment of the private property right if access should be granted. We view the consideration of [3] the availability of reasonably effective alternative means as especially significant in this balancing process.” 291 N. L. R. B., at 14.
The Board conceded that this analysis was unlikely to foster certainty and predictability in this corner of the law, but declared that “as with other legal questions involving multiple factors, the ‘nature of the problem, as revealed by unfolding variant situations, inevitably involves an evolutionary process for its rational response, not a quick, definitive formula as a comprehensive answer.’ ” Ibid, (quoting Electrical Workers v. NLRB, 366 U. S. 667, 674 (1961)).
Citing its role “as the agency with responsibility for implementing national labor policy,” the Board maintains in this case that Jean Country is a reasonable interpretation of the NLRA entitled to judicial deference. Brief for Respondent 18, and n. 8; Tr. of Oral Arg. 22. It is certainly true, and we have long recognized, that the Board has the “special function of applying the general provisions of the Act to the complexities of industrial life.” NLRB v. Erie Resistor Corp., 373 U. S. 221, 236 (1963); see also Phelps Dodge Corp. v. NLRB, 313 U. S. 177, 196-197 (1941). Like other administrative agencies, the NLRB is entitled to judicial deference when it interprets an ambiguous provision of a statute that it administers. See, e.g., NLRB v. Food & Commercial Workers, 484 U. S. 112, 123 (1987); cf. Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U. S. 837, 842-843 (1984).
Before we reach any issue of deference to the Board, however, we must first determine whether Jean Country — at least as applied to nonemployee organizational trespassing— is consistent with our past interpretation of § 7. “Once we have determined a statute’s clear meaning, we adhere to that determination under the doctrine of stare decisis, and we judge an agency’s later interpretation of the statute against our prior determination of the statute’s meaning.” Maislin Industries, U. S., Inc. v. Primary Steel, Inc., 497 U. S. 116, 131 (1990).
In Babcock, as explained above, we held that the Act drew a distinction “of substance,” 351 U. S., at 113, between the union activities of employees and nonemployees. In cases involving employee activities, we noted with approval, the Board “balanced the conflicting interests of employees to receive information on self-organization on the company’s property from fellow employees during nonworking time, with the employer’s right to control the use of his property.” Id., at 109-110. In cases involving nonemployee activities (like those at issue in Babcock itself), however, the Board was not permitted to engage in that same balancing (and we reversed the Board for having done so). By reversing the Board’s interpretation of the statute for failing to distinguish between the organizing activities of employees and nonemploy-ees, we were saying, in Chevron terms, that §7 speaks to the issue of nonemployee access to an employer’s property. Babcock’s teaching is straightforward: §7 simply does not protect nonemployee union organizers except in the rare case where “the inaccessibility of employees makes ineffective the reasonable attempts by nonemployees to communicate with them through the usual channels,” 351 U. S., at 112. Our reference to “reasonable” attempts was nothing more than a commonsense recognition that unions need not engage in extraordinary feats to communicate with inaccessible employees — not an endorsement of the view (which we expressly rejected) that the Act protects “reasonable” trespasses. Where reasonable alternative means of access exist, § 7’s guarantees do not authorize trespasses by nonemployee organizers, even (as we noted in Babcock, ibid.) “under . . . reasonable regulations” established by the Board.
Jean Country, which applies broadly to “all access cases,” 291 N. L. R. B., at 14, misapprehends this critical point. Its principal inspiration derives not from Babcock, but from the following sentence in Hudgens: “[T]he locus of th[e] accommodation [between §7 rights and private property rights] may fall at differing points along the spectrum depending on the nature and strength of the respective § 7 rights and private property rights asserted in any given context.” 424 U. S., at 522. From this sentence the Board concluded that it was appropriate to approach every case by balancing §7 rights against property rights, with alternative means of access thrown in as nothing more than an “especially significant” consideration. As explained above, however, Hud-gens did not purport to modify Babcock, much less to alter it fundamentally in the way Jean Country suggests. To say that our cases require accommodation between employees’ and employers’ rights is a true but incomplete statement, for the cases also go far in establishing the locus of that accommodation where nonemployee organizing is at issue. So long as nonemployee union organizers have reasonable access to employees outside an employer’s property, the requisite accommodation has taken place. It is only where such access is infeasible that it becomes necessary and proper to take the accommodation inquiry to a second level, balancing the employees’ and employers’ rights as described in the Hudgens dictum. See Sears, 436 U. S., at 205; Central Hardware, 407 U. S., at 545. At least as applied to nonem-ployees, Jean Country impermissibly conflates these two stages of the inquiry — thereby significantly eroding Bab-cock’s general rule that “an employer may validly post his property against nonemployee distribution of union literature,” 351 U. S., at 112. We reaffirm that general rule today, and reject the Board’s attempt to recast it as a multifactor balancing test.
c
The threshold inquiry in this case, then, is whether the facts here justify application of Babcock’s inaccessibility exception. The ALJ below observed that “the facts herein convince me that reasonable alternative means [of communicating with Lechmere’s employees] were available to the Union,” 295 N. L. R. B., at 99 (emphasis added). Reviewing the ALJ’s decision under Jean Country, however, the Board reached a different conclusion on this point, asserting that “there was no reasonable, effective alternative means available for the Union to communicate its message to [Lech-mere’s] employees.” Id., at 93.
We cannot accept the Board’s conclusion, because it “rest[s] on erroneous legal foundations,” Babcock, supra, at 112; see also NLRB v. Brown, 380 U. S. 278, 290-292 (1965). As we have explained, the exception to Babcock’s rule is a narrow one.' It does not apply wherever nontrespassory access to employees may be cumbersome or less-than-ideally effective, but only where “the location of a plant 'and the living quarters of the employees place the employees beyond the reach of reasonable union efforts to communicate with them,” 351 U. S., at 113 (emphasis added). Classic examples include logging camps, see NLRB v. Lake Superior Lumber Corp., 167 F. 2d 147 (CA6 1948); mining camps, see Alaska Barite Co., 197 N. L. R. B. 1023 (1972), enforced mem., 83 LRRM 2992 (CA9), cert. denied, 414 U. S. 1025 (1973); and mountain resort hotels, see NLRB v.S&H Grossinger’s Inc., 372 F. 2d 26 (CA2 1967). Babcock’s exception was crafted precisely to protect the § 7 rights of those employees who, by virtue of their employment, are isolated from the ordinary flow of information that characterizes our society. The union’s burden of establishing such isolation is, as we have explained, “a heavy one,” Sears, supra, at 205, and one not satisfied by mere conjecture or the expression of doubts concerning the effectiveness of nontrespassory means of communication.
The Board’s conclusion in this case that the union had no reasonable means short of trespass to make Lechmere’s employees aware of its organizational efforts is based on a misunderstanding of the limited scope of this exception. Because the employees do not reside on Lechmere’s property, they are presumptively not “beyond the reach,” Babcock, 351 U. S., at 113, of the union’s message. Although the employees live in a large metropolitan area (Greater Hartford), that fact does not in itself render them “inaccessible” in the sense contemplated by Babcock. See Monogram Models, Inc., 192 N. L. R. B. 705, 706 (1971). Their accessibility is suggested by the union’s success in contacting a substantial percentage of them directly, via mailings, phone calls, and home visits. Such direct contact, of course, is not a necessary element of “reasonably effective” communication; signs or advertising also may suffice. In this case, the union tried advertising in local newspapers; the Board said that this was not reasonably effective because it was expensive and might not reach the employees. 295 N. L. R. B., at 93. Whatever the merits of that conclusion, other alternative means of communication were readily available. Thus, signs (displayed, for example, from the public grassy strip adjoining Lechmere’s parking lot) would have informed the employees about the union’s organizational efforts. (Indeed, union organizers picketed the shopping center’s main entrance for months as employees came and went every day.) Access to employees, not success in winning them over,, is: the critical issue — although success, or lack thereof, may be relevant in determining whether reasonable access exists. Because the union in this case failed to establish the existence of any “unique obstacles,” Sears, 436 U. S., at 205-206, n. 41, that frustrated access to Lechmere’s employees, the Board erred in concluding that Lechmere committed an unfair labor practice by barring the nonemployee organizers from its property.
The judgment of the First Circuit is therefore reversed, and enforcement of the Board’s order is denied.
It is so ordered.
Lechmere had established this policy several years prior to the union’s organizing efforts. The store’s official policy statement provided, in relevant part:
“Non-associates [i. e., nonemployees] are prohibited from soliciting and distributing literature at all times anywhere on Company property, including parking lots. Non-associates have no right of access to the non-working areas and only to the public and selling areas of the store in connection with its public use.” Brief for Petitioner 7.
On each door to the store Lechmere had posted a 6- by 8-inch sign reading: “TO THE PUBLIC. No Soliciting, Canvassing, Distribution of Literature or Trespassing by Non-Employees in or on Premises.” App. 115— 116. Lechmere consistently enforced this policy inside the store as well as on the parking lot (against, among.Qthers, the Salvation Army and the Girl Scouts).
Under the (pre-Jean Country) Fairmont Hotel analysis applied by the ALJ, it was only where the employees’ § 7 rights and an employer’s property rights were deemed “relatively equal in strength,” Fairmont Hotel Co., 282 N. L. R. B. 139, 142 (1986), that the adequacy of nontrespassory means of communication became relevant. Because the ALJ found that the §7 rights involved here outweighed Lechmere’s property rights, he had no need to address the latter issue. He did so, he explained, only because of the possibility that his evaluation of the relative weights of the rights might not be upheld. 295 N. L. R. B. 94, 99 (1988).