JUSTICE O'CONNOR delivered the opinion of the Court.
This case presents the question whether Forest Service regulations, federal land use statutes and regulations, or the Coastal Zone Management Act of 1972 (CZMA), 16 U.S.C. §1451 et seq. (1982 ed. and Supp. III), preempt the California Coastal Commission's imposition of a permit requirement on operation of an unpatented mining claim in a national forest.
I
Granite Rock Company is a privately owned firm that mines chemical and pharmaceutical grade white limestone. Under the Mining Act of 1872, 17 Stat. 91, as amended, 30 U.S.C. § 22 et seq., a private citizen may enter federal lands to explore for mineral deposits. If a person locates a valuable mineral deposit on federal land, and perfects the claim by properly staking it and complying with other statutory requirements, the claimant "shall have the exclusive right of possession and enjoyment of all the surface included within the lines of their locations," 30 U.S.C. § 26, although the United States retains title to the land. The holder of a perfected mining claim may secure a patent to the land by complying with the requirements of the Mining Act and regulations promulgated thereunder, see 43 CFR § 3861.1 et seq. (1986), and, upon issuance of the patent, legal title to the land passes to the patent holder. Granite Rock holds unpatented mining claims on federally owned lands on and around Mount Pico Blanco in the Big Sur region of Los Padres National Forest.
From 1959 to 1980, Granite Rock removed small samples of limestone from this area for mineral analysis. In 1980, in accordance with federal regulations, see 36 CFR § 228.1 et seq. (1986), Granite Rock submitted to the Forest Service a 5-year plan of operations for the removal of substantial amounts of limestone. The plan discussed the location and appearance of the mining operation, including the size and shape of excavations, the location of all access roads, and the storage of any overburden. App. 27-34. The Forest Service prepared an Environmental Assessment of the plan. Id. at 38-53. The Assessment recommended modifications of the plan, and the responsible Forest Service Acting District Ranger approved the plan with the recommended modifications in 1981. Id. at 54. Shortly after Forest Service approval of the modified plan of operations, Granite Rock began to mine.
Under the California Coastal Act (CCA), Cal.Pub.Res.Code Ann. § 30000 et seq. (West 1986), any person undertaking any development, including mining, in the State's coastal zone must secure a permit from the California Coastal Commission. §§ 30106, 30600. According to the CCA, the Coastal Commission exercises the State's police power and constitutes the State's coastal zone management program for purposes of the federal CZMA, described infra at 480 U. S. 589 -590. In 1983, the Coastal Commission instructed Granite Rock to apply for a coastal development permit for any mining undertaken after the date of the Commission's letter. [ Footnote 1 ]
Granite Rock immediately filed an action in the United States District Court for the Northern District of California seeking to enjoin officials of the Coastal Commission from compelling Granite Rock to comply with the Coastal Commission permit requirement and for declaratory relief under 28 U.S.C. § 2201 (1982 ed., Supp. III). Granite Rock alleged that the Coastal Commission permit requirement was preempted by Forest Service regulations, by the Mining Act of 1872, and by the CZMA. Both sides agreed that there were no material facts in dispute. The District Court denied Granite Rock's motion for summary judgment, and dismissed the action. 690 F.Supp. 1361 (1984). The Court of Appeals for the Ninth Circuit reversed. 768 F.2d 1077 (1986). The Court of Appeals held that the Coastal Commission permit requirement was preempted by the Mining Act of 1872 and Forest Service regulations. The Court of Appeals acknowledged that the statute and regulations do not "go so far as to occupy the field of establishing environmental standards," specifically noting that Forest Service regulations "recognize that a state may enact environmental regulations in addition to those established by federal agencies," and that the Forest Service "will apply [the state standards] in exercising its permit authority." 768 F.2d at 1083. However, the Court of Appeals held that
an independent state permit system to enforce state environmental standards would undermine the Forest Service's own permit authority, and thus is preempted.
Ibid.
The Coastal Commission appealed to this Court under 28 U.S.C. § 1264(2). We postponed consideration of the question of jurisdiction to the hearing of the case on the merits, 476 U.S. 1094 (1986).
II
First, we address two jurisdictional issues. In the course of this litigation, Granite Rock's 6-year plan of operations expired. The controversy between Granite Rock and the Coastal Commission remains a live one, however, for two reasons. First, the Coastal Commission's 1983 letter instructed Granite Rock that a Coastal Commission permit was required for work undertaken after the date of the letter. App. 22-24. Granite Rock admitted that it has done work after that date. Id. at 83. Because the Coastal Commission asserts that Granite Rock needed a Coastal Commission permit for the work undertaken after the date of the Commission's letter, the Commission may require "reclamation for the mining that [has] occurred, measures to prevent pollution into the Little Sur River." Tr. of Oral Arg. 8. Granite Rock disputes the Coastal Commission's authority to require reclamation efforts. Second, Granite Rock stated in answer to interrogatories that its
investments and activities regarding its valid and unpatented mining claims require continuing operation beyond the present Plan of Operations,
and that it intended to conduct mining operations on the claim at issue "as long as [Granite Rock] can mine an economically viable and valuable mining deposit under applicable federal laws." App. 83-84. Therefore it is likely that Granite Rock will submit new plans of operations in the future. Even if future participation by California in the CZMA consistency review process, see infra at 480 U. S. 590 -591, or requirements placed on Granite Rock by the Forest Service called for compliance with the conditions of the Coastal Commission's permit, dispute would continue over whether the Coastal Commission itself, rather than the Federal Government, could enforce the conditions placed on the permit. This controversy is one capable of repetition, yet evading review. See Wisconsin Dept. of Industry v. Gould Inc., 475 U. S. 282, 475 U. S. 285, n. 3 (1986); Dunn v. Blumstein, 405 U. S. 330, 405 U. S. 333, n. 2 (1972). Accordingly, this case is not moot.
The second jurisdictional issue we must consider is whether this case is properly within our authority, under 28 U.S.C. § 1264(2), to review the decision of a federal court of appeals by appeal if a state statute is "held by a court of appeals to be invalid as repugnant to the Constitution, treaties or laws of the United States…." Statutes authorizing appeals are to be strictly construed. Silkwood v. Kerr-McGee Corp., 464 U. S. 238, 464 U. S. 247 (1984); Perry Education Assn. v. Perry Local Educators' Assn., 460 U. S. 37, 460 U. S. 43 (1983). As noted in Silkwood, supra, at 464 U. S. 247, "we have consistently distinguished between those cases in which a state statute is expressly struck down" as repugnant to the Constitution, treaties, or laws of the United States, and those cases in which "an exercise of authority under state law is invalidated without reference to the state statute." This latter group of cases do not fall within this Court's appellate jurisdiction.
In the present case, the Court of Appeals held that the particular exercise of the Coastal Commission permit requirement over Granite Rock's operation in a national forest was preempted by federal law. The Court of Appeals did not invalidate any portion of the CCA. In fact, it did not discuss whether the CCA itself actually authorized the imposition of a permit requirement over Granite Rock. See Cal.Pub. Res. Code Ann. § 30008 (West 1986) (limiting jurisdiction over federal lands to that which is "consistent with applicable federal… laws"). Accordingly, this case is one in which "an exercise of authority under state law is invalidated without reference to the state statute," Silkwood, supra, at 464 U. S. 247, and not within our § 1254(2) appellate jurisdiction. We therefore treat the jurisdictional statement as a petition for certiorari, 28 U.S.C. § 2103, and, having done so, grant the petition and reverse the judgment of the Court of Appeals.
III
Granite Rock does not argue that the Coastal Commission has placed any particular conditions on the issuance of a permit that conflict with federal statutes or regulations. Indeed, the record does not disclose what conditions the Coastal Commission will place on the issuance of a permit. Rather, Granite Rock argues, as it must, given the posture of the case, that there is no possible set of conditions the Coastal Commission could place on its permit that would not conflict with federal law -that any state permit requirement is per se preempted. The only issue in this case is this purely facial challenge to the Coastal Commission permit requirement.
The Property Clause provides that
Congress shall have Power to dispose of and make all needful Rules and Regulations respecting the Territory or other Property belonging to the United States.
U.S.Const., Art. IV, § 3, cl. 2. This Court has "repeatedly observed" that " [t]he power over the public land thus entrusted to Congress is without limitations.'" Kleppe v. New Mexico, 426 U. S. 529, 426 U. S. 639 (1976), quoting United States v. San Francisco, 310 U. S. 16, 310 U. S. 29 (1940). Granite Rock suggests that the Property Clause not only invests unlimited power in Congress over the use of federally owned lands, but also exempts federal lands from state regulation, whether or not those regulations conflict with federal law. In Kleppe, 426 U.S. at 426 U. S. 543, we considered "totally unfounded" the assertion that the Secretary of the Interior had even proposed such an interpretation of the Property Clause. We made clear that "the State is free to enforce its criminal and civil laws" on federal land so long as those laws do not conflict with federal law. Ibid. The Property Clause itself does not automatically conflict with all state regulation of federal land. Rather, as we explained in Kleppe:
Absent consent or cession, a State undoubtedly retains jurisdiction over federal lands within its territory, but Congress equally surely retains the power to enact legislation respecting those lands pursuant to the Property Clause. And when Congress so acts, the federal legislation necessarily overrides conflicting state laws under the Supremacy Clause.
Ibid. (citations omitted) (emphasis supplied). We agree with Granite Rock that the Property Clause gives Congress plenary power to legislate the use of the federal land on which Granite Rock holds its unpatented mining claim. The question in this case, however, is whether Congress has enacted legislation respecting this federal land that would preempt any requirement that Granite Rock obtain a California Coastal Commission permit. To answer this question, we follow the preemption analysis by which the Court has been guided on numerous occasions:
[S]tate law can be preempted in either of two general ways. If Congress evidences an intent to occupy a given field, any state law falling within that field is preempted. [ Pacific Gas & Electric Co. v. State Energy Resources Conservation & Development Comm'n, 461 U. S. 190,] 461 U. S. 203 -204 [(1983)]; Fidelity Federal Savings & Loan Assn. v. De la Cuesta, 458 U. S. 141, 458 U. S. 153 (1982); Rice v. Santa Fe Elevator Corp., 331 U. S. 218, 331 U. S. 230 (1947). If Congress has not entirely displaced state regulation over the matter in question, state law is still preempted to the extent it actually conflicts with federal law, that is, when it is impossible to comply with both state and federal law, Florida Lime & Avocado Growers, Inc. v. Paul, 373 U. S. 132, 373 U. S. 142 -143 (1963), or where the state law stands as an obstacle to the accomplishment of the full purposes and objectives of Congress, Hines v. Davidowitz, 312 U. S. 52, 312 U. S. 67 (1941).
Silkwood v. Kerr-McGee Corp., supra, at 464 U. S. 248.
A
Granite Rock and the United States as amicus have made basically three arguments in support of a finding that any possible state permit requirement would be preempted. First, Granite Rock alleges that the Federal Government's environmental regulation of unpatented mining claims in national forests demonstrates an intent to preempt any state regulation. Second, Granite Rock and the United States assert that indications that state land use planning over unpatented mining claims in national forests is preempted should lead to the conclusion that the Coastal Commission permit requirement is preempted. Finally, Granite Rock and the United States assert that the CZMA, by excluding federal lands from its definition of the coastal zone, declared a legislative intent that federal lands be excluded from all state coastal zone regulation. We conclude that these federal statutes and regulations do not, either independently or in combination, justify a facial challenge to the Coastal Commission permit requirement.
Granite Rock concedes that the Mining Act of 1872, as originally passed, expressed no legislative intent on the as-yet rarely contemplated subject of environmental regulation. Brief for Appellee 31-32. In 1955, however, Congress passed the Multiple Use Mining Act, 69 Stat. 367, 30 U.S.C. § 601 et seq., which provided that the Federal Government would retain and manage the surface resources of subsequently located unpatented mining claims. 30 U.S.C. § 612(b). Congress has delegated to the Secretary of Agriculture the authority to make "rules and regulations" to "regulate [the] occupancy and use" of national forests. 16 U.S.C. § 551. Through this delegation of authority, the Department of Agriculture's Forest Service has promulgated regulations so that "use of the surface of National Forest System lands" by those such as Granite Rock, who have unpatented mining claims authorized by the Mining Act of 1872, "shall be conducted so as to minimize adverse environmental impacts on National Forest System surface resources." 36 CFR §§ 228.1, 228.3(d) (1986). It was pursuant to these regulations that the Forest Service approved the Plan of Operations submitted by Granite Rock. If, as Granite Rock claims, it is the federal intent that Granite Rock conduct its mining unhindered by any state environmental regulation, one would expect to find the expression of this intent in these Forest Service regulations. As we explained in Hillsborough County v. Automated Medical Laboratories, Inc., 471 U. S. 707, 471 U. S. 718 (1985), it is appropriate to expect an administrative regulation to declare any intention to preempt state law with some specificity:
[B]ecause agencies normally address problems in a detailed manner and can speak through a variety of means,… we can expect that they will make their intentions clear if they intend for their regulations to be exclusive. Thus, if an agency does not speak to the question of preemption, we will pause before saying that the mere volume and complexity of its regulations indicate that the agency did in fact intend to preempt.
Upon examination, however, the Forest Service regulations that Granite Rock alleges preempt any state permit requirement not only are devoid of any expression of intent to preempt state law, but rather appear to assume that those submitting plans of operations will comply with state laws. The regulations explicitly require all operators within the national forests to comply with state air quality standards, 36 CFR § 228.8(a) (1986), state water quality standards, § 228.8(b), and state standards for the disposal and treatment of solid wastes, § 228.8(c). The regulations also provide that, pending final approval of the plan of operations, the Forest Service officer with authority to approve plans of operation
will approve such operations as may be necessary for timely compliance with the requirements of Federal and State laws.…
§ 228.5(b) (emphasis added). Finally, the final subsection of § 228.8, "[r]equirements for environmental protection," provides:
(h) Certification or other approval issued by State agencies or other Federal agencies of compliance with laws and regulations relating to mining operations will be accepted as compliance with similar or parallel requirements of these regulations.
(Emphasis supplied.)
It is impossible to divine from these regulations, which expressly contemplate coincident compliance with state law as well as with federal law, an intention to preempt all state regulation of unpatented mining claims in national forests. Neither Granite Rock nor the United States contends that these Forest Service regulations are inconsistent with their authorizing statutes.
Given these Forest Service regulations, it is unsurprising that the Forest Service team that prepared the Environmental Assessment of Granite Rock's plan of operation, as well as the Forest Service officer that approved the plan of operation, expected compliance with state as well as federal law. The Los Padres National Forest Environmental Assessment of the Granite Rock plan stated that "Granite Rock is responsible for obtaining any necessary permits which may be required by the California Coastal Commission." App. 46. The Decision Notice and Finding of No Significant Impact issued by the Acting District Ranger accepted Granite Rock's plan of operation with modifications, stating:
The claimant, in exercising his rights granted by the Mining Law of 1872, shall comply with the regulations of the Departments of Agriculture and Interior. The claimant is further responsible for obtaining any necessary permits required by State and/or county laws, regulations and/or ordinance.
Id. at 54.
B
The second argument proposed by Granite Rock is that federal land management statutes demonstrate a legislative intent to limit States to a purely advisory role in federal land management decisions, and that the Coastal Commission permit requirement is therefore preempted as an impermissible state land use regulation.
In 1976, two pieces of legislation were passed that called for the development of federal land use management plans affecting unpatented mining claims in national forests. Under the Federal Land Policy and Management Act of 1976 (FLPMA), 90 Stat. 2744, 43 U.S.C. § 1701 et seq. (1982 ed. and Supp. III), the Department of the Interior's Bureau of Land Management is responsible for managing the mineral resources on federal forest lands; under the National Forest Management Act (NFMA), 90 Stat. 2949, 16 U.S.C. §§ 1600-1614 (1982 ed. and Supp. III), the Forest Service, under the Secretary of Agriculture, is responsible for the management of the surface impacts of mining on federal forest lands. Granite Rock, as well as the Solicitor General, point to aspects of these statutes indicating a legislative intent to limit States to an advisory role in federal land management decisions. For example, the NFMA directs the Secretary of Agriculture to
develop, maintain, and, as appropriate, revise land and resource management plans for units of the National Forest System, coordinated with the land and resource management planning processes of State and local governments and other Federal agencies,
16 U.S.C. § 1604(a). The FLPMA directs that land use plans developed by the Secretary of the Interior "shall be consistent with State and local plans to the maximum extent the [Secretary] finds consistent with Federal law," and calls for the Secretary, "to the extent he finds practical," to keep apprised of state land use plans, and to "assist in resolving, to the extent practical, inconsistencies between Federal and non-Federal Government plans." 43 U.S.C. § 1712(c)(9).
For purposes of this discussion, and without deciding this issue, we may assume that the combination of the NFMA and the FLPMA preempts the extension of state land use plans onto unpatented mining claims in national forest lands. The Coastal Commission [ Footnote 2 ] asserts that it will use permit conditions to impose environmental regulation. See Cal.Pub.Res.Code Ann. § 30233 (West 1986) (quality of coastal waters); § 30253(2) (erosion); § 30263(3) (air pollution); § 30240(b) (impact on environmentally sensitive habitat areas).
While the CCA gives land use as well as environmental regulatory authority to the Coastal Commission, the state statute also gives the Coastal Commission the ability to limit the requirements it will place on the permit. The CCA declares that the Coastal Commission will "provide maximum state involvement in federal activities allowable under federal law or regulations…." Cal.Pub.Res.Code Ann. § 30004 (West 1986). Since the state statute does not detail exactly what state standards will and will not apply in connection with various federal activities, the statute must be understood to allow the Coastal Commission to limit the regulations it will impose in those circumstances. In the present case, the Coastal Commission has consistently maintained that it does not seek to prohibit mining of the unpatented claim on national forest land. See 768 F.2d at 1080 ("The Coastal Commission also argues that the Mining Act does not preempt state environmental regulation of federal land unless the regulation prohibits mining altogether…") (emphasis supplied); 590 F.Supp. at 1373 ("The [Coastal Commission] seeks not to prohibit or veto,' but to regulate [Granite Rock's] mining activity in accordance with the detailed requirements of the CCA…. There is no reason to find that the [Coastal Commission] will apply the CCA's regulations so as to deprive [Granite Rock] of its rights under the Mining Act"); Defendants' Memorandum of Points and Authorities in Opposition to Plaintiff's Motion for Summary Judgment in No. C-83-5137 (ND Cal.), pp. 41-42. ("Despite Granite Rock's characterization of Coastal Act regulation as a `veto' or ban of mining, Granite Rock has not applied for any coastal permit, and the State… has not indicated that it would in fact ban such activity…. [T]he question presented is merely whether the state can regulate uses, rather than prohibit them. Put another way, the state is not seeking to determine basic uses of federal land; rather, it is seeking to regulate a given mining use so that it is carried out in a more environmentally sensitive and resource-protective fashion").
The line between environmental regulation and land use planning will not always be bright; for example, one may hypothesize a state environmental regulation so severe that a particular land use would become commercially impracticable. However, the core activity described by each phrase is undoubtedly different. Land use planning in essence chooses particular uses for the land; environmental regulation, at its core, does not mandate particular uses of the land, but requires only that, however the land is used, damage to the environment is kept within prescribed limits. Congress has indicated its understanding of land use planning and environmental regulation as distinct activities. As noted above, 43 U.S.C. § 1712(c)(9) requires that the Secretary of the Interior's land use plans be consistent with state plans only "to the extent he finds practical." The immediately preceding subsection, however, requires that the Secretary's land use plans
provide for compliance with applicable pollution control laws, including State and Federal air, water, noise, or other pollution standards or implementation plans.
§ 1712(c)(8). Congress has also illustrated its understanding of land use planning and environmental regulation as distinct activities by delegating the authority to regulate these activities to different agencies. The stated purpose of part 228, subpart A of the Forest Service regulations, 36 CFR § 228.1 (1986), is to "set forth rules and procedures" through which mining on unpatented claims in national forests "shall be conducted so as to minimize adverse environmental impacts on National Forest System surface resources." The next sentence of the subsection, however, declares that
[i]t is not the purpose of these regulations to provide for the management of mineral resources; the responsibility for managing such resources is in the Secretary of the Interior.
Congress clearly envisioned that, although environmental regulation and land use planning may hypothetically overlap in some instances, these two types of activity would in most cases be capable of differentiation. Considering the legislative understanding of environmental regulation and land use planning as distinct activities, it would be anomalous to maintain that Congress intended any state environmental regulation of unpatented mining claims in national forests to be per se preempted as an impermissible exercise of state land use planning. Congress' treatment of environmental regulation and land use planning as generally distinguishable calls for this Court to treat them as distinct, until an actual overlap between the two is demonstrated in a particular case.
Granite Rock suggests that the Coastal Commission's true purpose in enforcing a permit requirement is to prohibit Granite Rock's mining entirely. By choosing to seek injunctive and declaratory relief against the permit requirement before discovering what conditions the Coastal Commission would have placed on the permit, Granite Rock has lost the possibility of making this argument in this litigation. Granite Rock's case must stand or fall on the question whether any possible set of conditions attached to the Coastal Commission's permit requirement would be preempted. As noted in the previous section, the Forest Service regulations do not indicate a federal intent to preempt all state environmental regulation of unpatented mining claims in national forests. Whether or not state land use planning over unpatented mining claims in national forests is preempted, the Coastal Commission insists that its permit requirement is an exercise of environmental regulation, rather than land use planning. In the present posture of this litigation, the Coastal Commission's identification of a possible set of permit conditions not preempted by federal law is sufficient to rebuff Granite Rock's facial challenge to the permit requirement. This analysis is not altered by the fact that the Coastal Commission chooses to impose its environmental regulation by means of a permit requirement. If the Federal Government occupied the field of environmental regulation of unpatented mining claims in national forests -concededly not the case -then state environmental regulation of Granite Rock's mining activity would be preempted, whether or not the regulation was implemented through a permit requirement. Conversely, if reasonable state environmental regulation is not preempted, then the use of a permit requirement to impose the state regulation does not create a conflict with federal law where none previously existed. The permit requirement itself is not talismanic.
C
Granite Rock's final argument involves the CZMA, 16 U.S.C. § 1451 et seq. (1982 ed. and Supp. III), through which financial assistance is provided to States for the development of coastal zone management programs. Section 304(a) of the CZMA, 16 U.S.C. § 1453(1), defines the coastal zone of a State, and specifically excludes from the coastal zone
lands the use of which is by law subject solely to the discretion of or which is held in trust by the Federal Government, its officers or agents.
The Department of Commerce, which administers the CZMA, has interpreted § 1453(1) to exclude all federally owned land from the CZMA definition of a State's coastal zone. 15 CFR § 923.33(a) (1986).
Granite Rock argues that the exclusion of
lands the use of which is by law subject solely to the discretion of or which is held in trust by the Federal Government, its officers or agents
excludes all federally owned land from the CZMA definition of a State's coastal zone, and demonstrates a congressional intent to preempt any possible Coastal Commission permit requirement as applied to the mining of Granite Rock's unpatented claim in the national forest land.
According to Granite Rock, because Granite Rock mines land owned by the Federal Government, the Coastal Commission's regulation of Granite Rock's mining operation must be limited to participation in a consistency review process detailed in the CZMA. Under the CZMA, once a state coastal zone management program has been approved by the Secretary of Commerce for federal administrative grants,
any applicant for a required Federal license or permit to conduct an activity affecting land or water uses in the coastal zone of that state shall provide in the application… a certification that the proposed activity complies with the state's approved program and that such activity will be conducted in a manner consistent with the [state] program.
16 U.S.C. § 1456(c)(3)(A). At the same time, the applicant must provide the State a copy of the certification. The State, after public notice and appropriate hearings, is to notify the federal agency concerned that the State concurs or objects to the certification. If the State fails to notify the federal agency within six months of receiving notification, it is presumed that the State concurs. If the State neither concurs nor is presumed to concur, the federal agency must reject the application unless the Secretary of Commerce finds that the application is consistent with the objectives of the CZMA or is "otherwise necessary in the interest of national security." Ibid.
In order for an activity to be subject to CZMA consistency review, the activity must be on a list that the State provides federal agencies, which describes the type of federal permit and license applications the State wishes to review. 16 CFR § 930.53 (1986). If the activity is unlisted, the State must, within 30 days of receiving notice of the federal permit application, inform the federal agency and federal permit applicant that the proposed activity requires CZMA consistency review. § 930.54. If the State does not provide timely notification, it waives the right to review the unlisted activity. In the present case, it appears that Granite Rock's proposed mining operations were not listed pursuant to § 930.63, and that the Coastal Commission did not timely notify the Forest Service or Granite Rock that Granite Rock's plan of operations required consistency review. App. 17. Therefore, the Coastal Commission waived its right to consistency review of the 1981-1986 plan of operations.
Absent any other expression of congressional intent regarding the preemptive effect of the CZMA, we would be required to decide, first, whether unpatented mining claims in national forests were meant to be excluded from the §