jected appellants' argument, relying on its earlier decisions in United States v. Farris, 624 F. 2d 890 (CA9 1980), cert. denied, 449 U. S. 1111 (1981), and Barona Group of Capitan Grande Band of Mission Indians, San Diego County, Cal. v. Duffy, 694 F. 2d 1185 (1982). 783 F. 2d, at 903. The court explained that whether a tribal activity is "a violation of the law of a state" within the meaning of OCCA depends on whether it violates the "public policy" of the State, the same test for application of state law under Pub. L. 280, and similarly concluded that bingo is not contrary to the public policy of California. 13

14

The Court of Appeals for the Sixth Circuit has rejected this view. United States v. Dakota, 796 F. 2d 186 (1986)." Since the OCCA standard is simply whether the gambling business is being operated in "violation of the law of a State," there is no basis for the regulatory/prohibitory distinction that it agreed is suitable in construing and applying Pub. L. 280. 796 F. 2d, at 188. And because enforcement of OCCA is an exercise of federal rather than state authority, there is no danger of state encroachment on Indian tribal sovereignty. Ibid. This latter observation exposes the flaw in appellants' reliance on OCCA. That enactment is indeed a federal law that, among other things, defines certain federal crimes over which the district courts have exclusive jurisdiction. 15 There is nothing in OCCA indicating that the States

18 In Farris, in contrast, the court had concluded that a gambling business, featuring blackjack, poker, and dice, operated by tribal members on the Puyallup Reservation violated the public policy of Washington; the United States, therefore, could enforce OCCA against the Indians.

"In Dakota, the United States sought a declaratory judgment that a gambling business, also featuring the playing of blackjack, poker, and dice, operated by two members of the Keweenaw Bay Indian Community on land controlled by the community, and under a license issued by the community, violated OCCA. The Court of Appeals held that the gambling business violated Michigan law and OCCA.

15 Title 18 U. S. C. §3231 provides: "The district courts of the United States shall have original jurisdiction, exclusive of the courts of the States, of all offenses against the laws of the United States."

are to have any part in enforcing federal criminal laws or are authorized to make arrests on Indian reservations that in the absence of OCCA they could not effect. We are not informed of any federal efforts to employ OCCA to prosecute the playing of bingo on Indian reservations, although there are more than 100 such enterprises currently in operation, many of which have been in existence for several years, for the most part with the encouragement of the Federal Government. 16 Whether or not, then, the Sixth Circuit is right and the Ninth Circuit wrong about the coverage of OCCA, a matter that we do not decide, there is no warrant for California to make arrests on reservations and thus, through OCCA, enforce its gambling laws against Indian tribes.

II

Because the state and county laws at issue here are imposed directly on the Tribes that operate the games, and are not expressly permitted by Congress, the Tribes argue that the judgment below should be affirmed without more. They rely on the statement in McClanahan v. Arizona State Tax Comm'n, 411 U. S. 164, 170-171 (1973), that "[s]tate laws generally are not applicable to tribal Indians on an Indian reservation except where Congress has expressly provided that State laws shall apply" (quoting United States Dept. of the Interior, Federal Indian Law 845 (1958)). Our cases, however, have not established an inflexible per se rule pre

16 See S. Rep. No. 99-493, p. 2 (1986). Federal law enforcement officers have the capability to respond to violations of OCCA on Indian reservations, as is apparent from Farris and Dakota. This is not a situation where the unavailability of a federal officer at a particular moment would likely result in nonenforcement. OCCA is directed at large-scale gambling enterprises. If state officers discover a gambling business unknown to federal authorities while performing their duties authorized by Pub. L. 280, there should be ample time for them to inform federal authorities, who would then determine whether investigation or other enforcement action was appropriate. A federal police officer is assigned by the Department of the Interior to patrol the Indian reservations in southern California. App. to Brief for Appellees D-1-D-7.

cluding state jurisdiction over tribes and tribal members in the absence of express congressional consent." "[U]nder certain circumstances a State may validly assert authority over the activities of nonmembers on a reservation, and.. in exceptional circumstances a State may assert jurisdiction over the on-reservation activities of tribal members." New Mexico v. Mescalero Apache Tribe, 462 U. S. 324, 331-332 (1983) (footnotes omitted).. Both Moe v. Confederated Salish and Kootenai Tribes, 425 U. S. 463 (1976), and Washington v. Confederated Tribes of Colville Indian Reservation, 447 U. S. 134 (1980), are illustrative. In those decisions

we held that, in the absence of express congressional permission, a State could require tribal smokeshops on Indian reservations to collect state sales tax from their non-Indian

"In the special area of state taxation of Indian tribes and tribal members, we have adopted a per se rule. In Montana v. Blackfeet Tribe, 471 U. S. 759 (1985), we held that Montana could not tax the Tribe's royalty interests in oil and gas leases issued to non-Indian lessees under the Indian Mineral Leasing Act of 1938. We stated: "In keeping with its plenary authority over Indian affairs, Congress can authorize the imposition of state taxes on Indian tribes and individual Indians. It has not done so often, and the Court consistently has held that it will find the Indians' exemption from state taxes lifted only when Congress has made its intention to do so unmistakably clear." Id., at 765. We have repeatedly addressed the issue of state taxation of tribes and tribal members and the state, federal, and tribal interests which it implicates. We have recognized that the federal tradition of Indian immunity from state taxation is very strong and that the state interest in taxation is correspondingly weak. Accordingly, it is unnecessary to rebalance these interests in every case. In Mescalero Apache Tribe v. Jones, 411 U. S. 145, 148 (1973), we distinguished state taxation from other assertions of state jurisdiction. We acknowledged that we had made repeated statements "to the effect that, even on reservations, state laws may be applied unless such application would interfere with reservation self-government or would impair a right granted or reserved by federal law. . . . Even so, in the special area of state taxation, absent cession of jurisdiction or other federal statutes permitting it, there has been no satisfactory authority for taxing Indian reservation lands or Indian income from activities carried on within the boundaries of the reservation, and McClanahan v. Arizona State Tax Comm'n, [411 U. S. 164

customers. Both cases involved nonmembers entering and purchasing tobacco products on the reservations involved. The State's interest in assuring the collection of sales taxes from non-Indians enjoying the off-reservation services of the State was sufficient to warrant the minimal burden imposed on the tribal smokeshop operators.

18

This case also involves a state burden on tribal Indians in the context of their dealings with non-Indians since the question is whether the State may prevent the Tribes from making available high stakes bingo games to non-Indians coming from outside the reservations. Decision in this case turns on whether state authority is pre-empted by the operation of federal law; and "[s]tate jurisdiction is pre-empted. . . if it interferes or is incompatible with federal and tribal interests reflected in federal law, unless the state interests at stake are sufficient to justify the assertion of state authority." Mescalero, 462 U. S., at 333, 334. The inquiry is to proceed in light of traditional notions of Indian sovereignty and the congressional goal of Indian self-government, including its "overriding goal" of encouraging tribal self-sufficiency and economic development. Id., at 334-335.19 See also,

(1973)], lays to rest any doubt in this respect by holding that such taxation is not permissible absent congressional consent." Ibid. (emphasis added).

18 JUSTICE STEVENS appears to embrace the opposite presumption—that state laws apply on Indian reservations absent an express congressional statement to the contrary. But, as we stated in White Mountain Apache Tribe v. Bracker, 448 U. S. 136, 151 (1980), in the context of an assertion of state authority over the activities of non-Indians within a reservation, "[t]hat is simply not the law." It is even less correct when applied to the activities of tribes and tribal members within reservations.

19 In New Mexico v. Mescalero Apache Tribe, 462 U. S., at 335, n. 17, we discussed a number of the statutes Congress enacted to promote tribal self-government. The congressional declarations of policy in the Indian Financing Act of 1974, as amended, 25 U. S. C. § 1451 et seq. (1982 ed. and Supp. III), and in the Indian Self-Determination and Education Assistance Act of 1975, as amended, 25 U. S. C. § 450 et seq. (1982 ed. and Supp. III), are particularly significant in this case: "It is hereby declared to be the policy of Congress... to help develop and utilize Indian resources, both physical and human, to a point where the Indians will fully exercise responsibil

Iowa Mutual Insurance Co. v. LaPlante, ante, p. 9; White Mountain Apache Tribe v. Bracker, 448 U. S. 136, 143 (1980).

These are important federal interests. They were reaffirmed by the President's 1983 Statement on Indian Policy.20 More specifically, the Department of the Interior, which has the primary responsibility for carrying out the Federal Government's trust obligations to Indian tribes, has sought to implement these policies by promoting tribal bingo enterprises. Under the Indian Financing Act of 1974, 25

21

ity for the utilization and management of their own resources and where they will enjoy a standard of living from their own productive efforts comparable to that enjoyed by non-Indians in neighboring communities." 25 U. S. C. § 1451. Similarly, "[t]he Congress declares its commitment to the maintenance of the Federal Government's unique and continuing relationship with and responsibility to the Indian people through the establishment of a meaningful Indian self-determination policy which will permit an orderly transition from Federal domination of programs for and services to Indians to effective and meaningful participation by the Indian people in the planning, conduct, and administration of those programs and services." 25 U. S. C. § 450a(b).

20

"It is important to the concept of self-government that tribes reduce their dependence on Federal funds by providing a greater percentage of the cost of their self-government." 19 Weekly Comp. of Pres. Doc. 99 (1983).

"The Court of Appeals relied on the following official declarations. 783 F.2d, at 904-905. A policy directive issued by the Assistant Secretary of the Interior on March 2, 1983, stated that the Department would "strongly oppose" any proposed legislation that would subject tribes or tribal members to state gambling regulation. "Such a proposal is inconsistent with the President's Indian Policy Statement of January 24, 1983. . . . A number of tribes have begun to engage in bingo and similar gambling operations on their reservations for the very purpose enunciated in the President's Message. Given the often limited resources which tribes have for revenue-producing activities, it is believed that this kind of revenueproducing possibility should be protected and enhanced." The court also relied on an affidavit submitted by the Director of Indian Services, Bureau of Indian Affairs, on behalf of the Tribes' position:

"It is the department's position that tribal bingo enterprises are an appropriate means by which tribes can further their economic selfsufficiency, the economic development of reservations and tribal self