This appeal arises out of two suits, consolidated for trial, brought by appellees against the Jicarilla Apache Tribe and its Tribal Council (the Tribe). Appellees (lessees), who are non-Indians, produce oil and gas from within the Tribe’s reservation pursuant to leases granted them under the auspices of the Secretary of the Interior. After the Tribe enacted an oil and gas severance tax to be measured by production from oil and gas wells within the reservation, lessees sued the Tribe and Secretary of Interior, Cecil Andrus,1 seeking a declaratory judgment and injunction that would prohibit enforcement of this tax. After a non-jury trial, the judge permanently enjoined enforcement declaring the tax “illegal, unconstitutional, invalid and void.”
The issues on appeal are whether,
(1) the district court had jurisdiction over the claims against the Tribe and the Secretary of the Interior,
(2) the Tribe has the inherent power to levy the severance tax,
(3) the tax violates the Commerce Clause of the United States Constitution, and
(4) Congress preempted tribal taxation.
The Jicarilla Apache Tribe is an Indian Tribe occupying an executive order reservation in northwestern New Mexico. The Tribal Council is the legislative arm of the Tribe’s government. In 1968 the Tribe adopted a revised constitution pursuant to the Indian Reorganization Act of 1934, §§ 16,17, 25 U.S.C. §§ 476, 477. Article XI of that constitution provides, in pertinent part,
Section 1. The inherent powers of the Jicarilla Apache Tribe, including those conferred by Section 16 of the Act of June 18,1934, (48 Stat. 984), as amended, shall vest in the tribal council and shall be exercised thereby subject only to limitations imposed by the Constitution of the United States, applicable Federal statutes and regulations of the Department of the Interior and the restrictions established by this revised constitution.
(e) Taxes and Fees. The tribal council may levy and collect taxes and fees on tribal members, and may enact ordinances, subject to approval by the Secretary of the Interior, to impose taxes and fees on non-members of the tribe doing business on the reservation.
The revised constitution was approved by the Under Secretary of the Interior in 1969.
In 1976 the Tribal Council adopted an ordinance imposing a severance tax on “any oil and natural gas severed, saved and removed from Tribal lands.” The operators are required to pay the tax, which is due at the time of severance and is payable monthly. The tax rate is assessed at the wellhead per barrel of crude oil and per million BTU of natural gas “sold or transported off the Reservation.” “Royalty gas, oil or condensate taken by the Tribe in kind, and used by the Tribe” is exempt from taxation. The Secretary, through the Acting Area Director of the Bureau of Indian Affairs, formally approved the tribal ordinance in December of 1976.
Among the trial court’s findings of fact are the following: Approximately 80% of the oil and gas produced by lessees is shipped interstate for sale outside the state of New Mexico; the tax would generate *540o ver two million dollars annually; the lessees would be able to pass the majority of the tax burden on to their customers; if the lessees are required to absorb the tax, the ability of some of the lessees to operate profitably some of the existing oil wells on the reservation would be substantially limited; those lessees not able to profitably operate wells “would be required to shut down such wells resulting in a loss of natural resources and an unjust return of the wells to the Jicarilla Apache Tribe”; and the tax burden on the price of oil and gas would be more than 29% of the interstate price of old gas and over 12.5% of the price of old oil.
Based upon these findings the trial court held that (1) neither tribal sovereignty nor the Indian Reorganization Act of 1934 empower the Tribe to enact the tax; (2) 25 U.S.C. § 398c grants the State of New Mexico the exclusive right to tax lessees; and (3) the tax discriminates against and constitutes a multiple burden on interstate commerce in violation of the Commerce Clause.
I
Before proceeding to the merits, we must consider two jurisdictional questions— whether the trial court had jurisdiction to enjoin the Secretary of the Interior from taking any action to enforce the tax, and whether the court had jurisdiction over the Tribe.
Lessees sued the Secretary on the basis that in approving the Tribe’s tax ordinance he violated the Administrative Procedure Act (APA), 5 U.S.C. §§ 701 et seq. The APA is not an independent grant of federal jurisdiction. Califano v. Sanders, 430 U.S. 99, 105-07, 97 S.Ct. 980, 984-85, 51 L.Ed.2d 192 (1977). Since only injunctive relief is sought, an action can be maintained against the Secretary under the 1976 amendments to 5 U.S.C. § 702. Appellees admit waiving the defense that the Secretary improperly delegated his approval function to the local official of the Bureau of Indian Affairs. The only arguments made in this Court that the Secretary acted unlawfully under the APA go to the merits of the tax and are treated hereafter.
The Tribe asserts that under the doctrine of sovereign immunity it could not be sued and therefore the trial court was without jurisdiction,2 citing Santa Clara Pueblo v. Martinez, 436 U.S. 49, 98 S.Ct. 1670, 56 L.Ed.2d 106 (1978) and United States v. United States Fidelity & Guar. Co., 309 U.S. 506, 60 S.Ct. 653, 84 L.Ed. 894 (1940). Those cases clearly hold a tribe cannot be sued absent consent. See also Puyallup Tribe, Inc. v. Department of Game, 433 U.S. 165, 97 S.Ct. 2616, 53 L.Ed.2d 667 (1977). Here the Tribal Council, as the duly constituted legislative body of the Tribe, by the terms of the severance tax ordinance, expressly consented to suits against the Tribe in the United States District Court or in the Jicarilla Apache Tribal Court. The ordinance was approved by the representative of the Secretary of the Interior. The question is whether this constitutes effective consent.
We see no reason in principle or in law to conclude a Tribe that has taken advantage of Congress’s encouragement to organize for purposes of providing for its common welfare under 25 U.S.C. § 476, has adopted a constitution, and has formally attempted to waive its sovereign immunity in this ordinance, may not do so. We believe the grant of power under the Indian Reorganization Act of 1934 is broad enough to encompass express waiver of sovereign immunity to suit when the ordinance, as here, has been specifically approved by the Secretary of Interior. We therefore hold the trial court had jurisdiction over the Tribe.3
*541II
In treating the merits of this appeal, we first consider the basic question whether the Tribe may impose a tax upon nonmembers of the Tribe doing business within the Tribe’s territorial jurisdiction. The tax instituted by the Tribe here is an excise or privilege tax imposed on the occupation of severing oil and gas from tribal land, measured by quantity produced. See Ohio Oil Co. v. Conway, 281 U.S. 146, 50 S.Ct. 310, 74 L.Ed. 775 (1930); Flynn, Welch & Yates, Inc. v. State Tax Comm’n, 38 N.M. 131, 28 P.2d 889 (1934). See also Oliver Iron Mining Co. v. Lord, 262 U.S. 172, 43 S.Ct. 526, 67 L.Ed. 929 (1923). Since no treaty or act of Congress specifically authorizes the exercise of such a taxing power, we must decide whether that power is among those “vested in any Indian Tribe or tribal council by existing law,” Indian Reorganization Act of 1934, § 16, 25 U.S.C. § 476, i. e., whether the Tribe has the inherent power to levy this tax. In making this determination we recognize the fundamental principle that the power of taxation, which is essential to the very existence of self-government, is an attribute of sovereignty and extends generally to all that is within that government’s territorial jurisdiction. M’Culloch v. Maryland, 17 U.S. (4 Wheat.) 316, 428-29, 4 L.Ed. 579 (1819).
It has long been recognized that Indian tribes, although once self-governing political nations, no longer possess the full attributes of sovereignty. Oliphant v. Suquamish Indian Tribe, 435 U.S. 191, 98 S.Ct. 1011, 55 L.Ed.2d 209 (1978); The Cherokee Nation v. Georgia, 30 U.S. (5 Pet.) 1, 8 L.Ed. 25 (1831). Nevertheless, the tribes are “unique aggregations possessing attributes of sovereignty over both their members and their territory.” United States v. Mazurie, 419 U.S. 544, 557, 95 S.Ct. 710, 717, 42 L.Ed.2d 706 (1975); Worcester v. Georgia, 31 U.S. (6 Pet.) 515, 557, 8 L.Ed. 483 (1832). They retain those powers of self-government not voluntarily relinquished by treaty, not divested by Congress in the exercise of its plenary authority over them, or not inconsistent with the superior interests of the United States as a sovereign nation. Oli-phant, 435 U.S. at 208-09, 98 S.Ct. at 1020-21; United States v. Wheeler, 435 U.S. 313, 323, 98 S.Ct. 1079, 1086, 55 L.Ed.2d 303 (1978).
While the Supreme Court has not passed directly upon the question before this Court, it has determined that certain powers were not retained by the tribes upon their incorporation because of the superior interests of the United States. It has long been established, for example, that the tribes, though rightful occupants of the soil, may not - convey it at their will, superior title having vested in the United States. Johnson and Graham’s Lessee v. M’Intosh, 21 U.S. (8 Wheat.) 543, 5 L.Ed. 681 (1823). Because of the United States interest in protecting its external political boundaries, the tribes as sovereign entities may not deal with foreign nations. The Cherokee Nation v. Georgia, 30 U.S. (5 Pet.) 1,17-18, 8 L.Ed. 25 (1831). Most recently, the Supreme Court determined that the tribes also gave up the power to exercise criminal jurisdiction over non-Indians, on the ground the power of the tribes to restrict the personal liberty of United States citizens’ conflicts with the federal government’s overriding interest in protecting its citizens “from unwarranted intrusions on their personal liberty.” Oliphant v. Suquamish Indian Tribe, 435 U.S. 191, 210, 98 S.Ct. 1011, 1021, 55 L.Ed.2d 209 (1978).
We do not find that tribal tax legislation in the context of this case necessarily and in every instance implicates a sovereign federal interest in the same way criminal adjudication, sale of tribal land, and governmental dealings with foreign nations does. The federal taxing power is in no way impinged; clearly the federal government can *542tax non-Indians or Indians within the reservation whether or not the Tribe levies this tax. Nor is there a general sovereign interest in preventing persons from being taxed by governmental entities other than itself.
A national, if not sovereign, interest in preventing deprivations of property without due process is manifested in the Fifth and Fourteenth Amendments. In the context of taxing, however, that interest is implicated only in the extremely rare case in which the taxing power is so abused the result is in reality not a tax, “but constitutes, in substance and effect, the direct exertion of a different and forbidden power, as, for example, the confiscation of property.” A Magnano Co. v. Hamilton, 292 U.S. 49, 44, 54 S.Ct. 599, 601, 78 L.Ed. 1109 (1934). See also City of Pittsburgh v. Alco Parking Corp., 417 U.S. 369, 94 S.Ct. 2291, 41 L.Ed.2d 132 (1974); Southwestern Oil Co. v. Texas, 217 U.S. 114, 30 S.Ct. 496, 54 L.Ed. 688 (1910). That is not the situation in the instant case.
Neither can we conclude that the “national interest in free and open trade” between the states, expressed by the Commerce Clause of the Constitution precludes tribal taxation. See Boston Stock Exch. v. State Tax Comm’n, 429 U.S. 318, 329, 97 S.Ct. 599, 606, 50 L.Ed.2d 514 (1977). Just as the clause serves only as a limitation on state taxation powers, id at 329, 97 S.Ct. at 606, it limits but does not destroy tribal powers of taxation.' See Part III, infra.
We recognize that in recent decisions bearing on the issue of inherent powers of Indian Tribes, the Supreme Court has occasionally employed language suggesting that Indians are without inherent powers over any nonmembers of their tribe. See Wheeler, 435 U.S. at 326, 98 S.Ct. at 1087; Oli-phant, 435 U.S. at 208-11, 98 S.Ct. at 1020-22. For instance, the Court in Wheeler described powers not retained by tribes as those that “would necessarily be lost by virtue of a tribe’s dependent status.” 435 U.S. at 326, 98 S.Ct. at 1088. For several reasons we do not believe this language was intended to dispose of a case like the one at issue here.
First, the formulation seems to be merely descriptive of the conclusion that in certain circumstances powers were not retained, and is not a test for determining the existence of inherent powers. The critical factor in the cases is whether important interests of the United States, other than Congress’s basic interest in regulating the affairs of the Indians, conflict with assertions of tribal authority. If the test is whether the asserted tribal power is inconsistent with its dependent status, then the focal point becomes the tribal position, which is always one of dependence upon the United States. Carried to its logical conclusion, such a test would mean that a tribe possesses no inherent powers even over its members, because the tribe’s very existence would depend upon affirmative enabling legislation by Congress. To the extent a tribe could exert power over its members, that power could only derive from the tribe’s existence as a private, voluntary association. These conclusions are fundamentally inconsistent, of course, with the teachings of other decisions of the Court. The Court has expressly rejected the contention the tribes are no more than private, voluntary associations, United States v. Mazurie, 419 U.S. 544, 557, 95 S.Ct. 710, 717, 42 L.Ed.2d 706 (1975), and has consistently held that tribal powers of self-government are inherent, derived from the tribe’s original status as independent sovereign nations. E. g., United States v. Wheeler, 435 U.S. 313, 322-323, 98 S.Ct. 1079, 1086, 55 L.Ed.2d 303 (1978); Talton v. Mayes, 163 U.S. 376, 16 S.Ct. 986, 41 L.Ed. 196 (1896).
Also persuasive are Supreme Court decisions to the effect that the tribe’s retained powers have at least some elements of territoriality. As early as 1823 the Court recognized in Johnson and Graham’s Lessee v. M’Intosh, 21 U.S. (8 Wheat.) 543, 5 L.Ed. 681 (1923), that voluntary transactions of nonmembers with the Tribes or their members within the confines of the reservation would subject that nonmember, at least regarding that transaction, to the laws of the tribe. Id. at 593. Similarly, Williams v. Lee, 358 U.S. 217, 79 S.Ct. 269, 3 L.Ed.2d *543251 (1959), held that a state court was without jurisdiction to hear a simple contract action brought by a nonmember against an Indian concerning a transaction entered into on the reservation. The Court’s stated rationale was premised in part upon the territorial aspect of the tribe’s right to self-government.
There can be no doubt that to allow the exercise of state jurisdiction here would undermine the authority of the tribal courts over Reservation affairs and hence would infringe on the right of the Indians to govern themselves. It is immaterial that respondent is not an Indian. He was on the Reservation and the transaction with an Indian took place there. . The cases in this Court have consistently guarded the authority of Indian governments over their reservations.
Id. at 223, 79 S.Ct. at 272 (citations omitted). See also United States v. Mazurie, 419 U.S. 544, 95 S.Ct. 710, 42 L.Ed.2d 706 (1975). While the territorial element of inherent tribal power is not necessarily exclusive, see, e. g., Moe v. Confederated Salish & Kootenai Tribes, 425 U.S. 463, 96 S.Ct. 1634, 48 L.Ed.2d 96 (1976); Thomas v. Gay, 169 U.S. 264, 18 S.Ct. 340, 42 L.Ed. 740 (1898), and may not exist in some circumstances, see Oliphant v. Suquamish Indian Tribe, 435 U.S. 191, 98 S.Ct. 1011, 55 L.Ed.2d 209 (1978), we do not think the decisions eliminate this aspect of tribal powers.
We are also persuaded by “the commonly shared presumption of Congress, the Executive Branch, and the lower federal courts,” Oliphant, 435 U.S. at 206, 98 S.Ct. at 1019, that the tribes retain the power to levy a tax that falls upon nonmembers doing business on the reservation. Prior to the Indian Reorganization Act of 1934, 25 U.S.C. § 476 (the Act), which was intended to facilitate tribal self-government, one decision by the Supreme Court and three by the Eighth Circuit approved imposition of tribal taxes on nonmembers doing business on the reservation. See Morris v. Hitchcock, 194 U.S. 384, 24 S.Ct. 712, 48 L.Ed. 1030 (1904); Buster v. Wright, 135 F. 947 (8th Cir. 1905), appeal dismissed without opinion, 203 U.S. 599, 27 S.Ct. 777, 51 L.Ed. 334 (1906); Max-ey v. Wright, 105 F. 1003 (8th Cir.), aff’g 3 Ind.T. 243, 54 S.W. 807 (1900); Crabtree v. Madden, 54 F. 426 (8th Cir. 1893). The Attorney General of the United States also approved similar taxes. E. g., Cherokee Indians — Export Tax on Hay, 23 Op.Att’y Gen. 528 (1901); Choctaw and Chickasaw Permit Laws, 18 Op.Att’y Gen. 34 (1884).
The parties to this appeal forcefully dispute the characterization of these decisions — the Tribe argues these decisions involved the inherent power to tax; the lessees argue they merely support the proposition that tribes have the proprietary, but not sovereign, right to exact fees from persons desiring to enter the reservation and do business therein. From our reading of the cases and opinions, we conclude that the decisions were grounded upon tribal sovereignty, with the exception of Choctaw and Chickasaw Permit Laws, 18 Op.Att’y Gen. 34 (1884). But two different sovereign powers have been relied upon — the power to tax, e. g., Cherokee Indians — Export Tax on Hay, 23 Op.Att’y Gen. 528 (1901), or the power to exclude nonmembers from the reservation and set the terms upon which such persons could enter and do business therein. E. g., Buster v. Wright, 135 F. at 950. The Supreme Court in Morris v. Hitchcock appears to have recognized both theories. 194 U.S. at 389-93, 24 S.Ct. at 713-15.
The case before us presents the bald issue of an Indian tribe’s taxing power without benefit of reservations of authority in a treaty. Thus, it seems important to ascertain whether particular treaties influenced the decisions discussed above. Although the United States did not always require tribes to give up the power to exercise civil jurisdiction over nonmembers and their property within the reservation, see, e. g., Jurisdiction of the Courts of the Choctaw Nation, 7 Op.Att’y Gen. 174, 176 (1855), nearly all of these tribes had done so. See, e. g., Morris v. Hitchcock, 21 App.D.C. 565, 593 (1903), aff’d, 194 U.S. 384, 24 S.Ct. 712, 48 L.Ed. 1030 (1904). Yet throughout the decisions is the sometimes explicit and sometimes implicit assumption that tribal *544exercise of power over nonmembers doing business on the reservation in connection with that business did not offend the interests of the United States and was a sovereign right retained by the tribes. Two cases decided by the Eighth Circuit after passage of the Act expressly upholding tribal taxes on the theory of the power of taxation share this assumption. Barta v. Oglala Sioux Tribe, 259 F.2d 553 (8th Cir. 1958), cert., denied, 358 U.S. 932, 79 S.Ct. 320, 3 L.Ed.2d 304 (1959); Iron Crow v. Oglala Sioux Tribe, 231 F.2d 89 (8th Cir. 1956).
Congress also apparently recognized tribal power to tax nonmembers within the reservation when it passed section 16 of the Act, which confirmed the existence of sovereign tribal powers generally. In hearings conducted prior to passage of the Act, Congress was apprised of the holding of Buster v. Wright, 135 F. 947 (8th Cir. 1905). See To Grant To Indians Living Under Federal Tutelage The Freedom To Organize For Purposes of Local Self-Government and Economic Enterprise: Hearings on S. 2755 and S. 3645 Before The Senate Comm, on Indian Affairs, 73d Cong., 2d Sess. 269-70 (1934). Solicitor Margold of the Department of Interior, in an opinion, considered the intent of Congress in its reference in section 16, to “all powers vested in any Indian tribe or tribal council by existing law.” Among those retained powers, he concluded that
[cjhief among the powers of sovereignty recognized as pertaining to an Indian Tribe is the power of taxation. Except where Congress has provided otherwise, this power may be exercised over members of the tribe and over nonmembers, so far as such nonmembers may accept privileges of trade, residence, etc., to which taxes may be attached as conditions.
Powers of Indian Tribes, 55 Interior Dec. 14, 46 (1934). This opinion, virtually contemporaneous with the Act, is persuasive evidence that neither Congress nor the Department of Interior believed a tribal taxing power would conflict with the interests of the United States. ' See also United States Department of the Interior, Federal Indian Law 435-39 (1958); 1 Final Report of the American Indian Policy Review Comm’n 154-58, 178-82 (1977). Consistent with its interpretation of the Act, the Department approved the tax involved in this case. As the agency charged with construction of the Act in the course of its actual execution, the Department’s conclusion that Indian tribes retain the power to levy a tax of the type involved here deserves great respect. See Northern Cheyenne Tribe v. Hollowbreast, 425 U.S. 649, 660, 96 S.Ct. 1793, 1799, 48 L.Ed.2d 274 (1976).
Except for the dollar sums involved, which are irrelevant, see City of Pittsburgh v. Alco Parking Corp., 417 U.S. 369, 94 S.Ct. 2291, 41 L.Ed.2d 132 (1974), we see no essential difference between the privilege taxes here levied and those approved by the Supreme Court in Morris v. Hitchcock and in the Eighth Circuit cases cited above. For all the reasons discussed above, we conclude that the Tribe has the inherent power to levy a privilege tax on the occupation of severing oil and gas from reservation land even thoügh the tax falls on nonmembers.
Ill
We now consider the argument that the severance tax violates the Commerce Clause. The Constitution empowers Congress to “regulate Commerce with foreign Nations, and among the several states, and with the Indian Tribes.” U.S.Const. art. I, § 8, cl. 3. We believe the national interest manifested in the Commerce Clause is not sufficient to preclude the tribes’ power to tax, but this clause of its own force limits the power of the tribes as well as the states. See Boston Stock Exch. v. State Tax Comm’n, 429 U.S. 318, 328, 97 S.Ct. 599, 606, 50 L.Ed.2d 514 (1977). It has long been established that the tribes constitute a separate category within that clause. The Cherokee Nation v. Georgia, 30 U.S. (5 Pet.) 1, 18-19, 8 L.Ed. 25 (1831). Since the tribes are not “states,” see id. at 16, United States v. Wheeler, 435 U.S. 313, 98 S.Ct. 1079, 55 L.Ed.2d 303 (1978), and necessarily are lo*545cated within the boundaries of one or more states, they are not subject directly to those doctrines implementing the phrase “among the states.”
It appears that no court has analyzed how the tribes are limited in their taxing power by the Indian Commerce Clause. We hold the standard to be used in applying that clause is whether a tribe’s tax legislation infringes upon the national interest in maintaining the free flow of interstate trade. Our view is that this national interest is measured by traditional analyses. The trial court found the tax imposed by the Tribe both discriminates against interstate commerce and constitutes a multiple burden on commerce. We treat first the discrimination question.
The trial court’s stated reason for holding the tax discriminates against interstate commerce is that the tax “is levied only against natural gas, crude oil or condensate which is produced on the reservation and sold or transported off the reservation.” This reason, which simply tracks the language of the ordinance, can be interpreted in two ways.
The first interpretation is that the tax provides “a direct commercial advantage to local business.” Boston Stock Exch. v. State Tax Comm’n, 429 U.S. 318, 329, 97 S.Ct. 599, 607, 50 L.Ed.2d 514 (1977) (quoting Northwestern States Portland Cement Co. v. Minnesota, 358 U.S. 450, 458, 79 S.Ct. 357, 362, 3 L.Ed.2d 421 (1959)). Although there actually is no Indian production here, the ordinance by its terms would apply to any operator engaged in severing the subject resources within the reservation. Apparently, the trial court viewed the provision exempting “[rjoyalty gas, oil or condensate taken by the Tribe in kind, and used by the Tribe” as the requisite local preference. We disagree. Subjecting royalty products the Tribe would receive to its own tax would be a fruitless and wasteful act. We therefore think the exemption is permissible.
Second, in view of the trial court’s finding that eighty percent of the hydrocarbons produced on the reservation entered interstate commerce, which we accept as true for purposes of this appeal, the court’s conclusion of law can mean it believed the tax is to be levied on the privilege of engaging in interstate commerce itself. Were this correct, the standards of Complete Auto Transit, Inc. v. Brady, 430 U.S. 274, 279, 97 S.Ct. 1076, 1079, 51 L.Ed.2d 326 (1977), and Department of Rev. v. Association of Wash. Stevedoring Cos., 435 U.S. 734, 98 S.Ct. 1388, 55 L.Ed.2d 682 (1978), would be applicable.4 However, it is settled that an occupation or privilege tax on the mining or severing of natural resources, although closely connected with interstate commerce, is a local activity properly subject to local taxation. Oliver Iron Mining Co. v. Lord, 262 U.S. 172, 43 S.Ct. 526, 67 L.Ed. 929 (1923). See Dunbar-Stanley Studios, Inc. v. Alabama, 383 U.S. 537, 541, 89 S.Ct. 757, 760, 21 L.Ed.2d 759 (1969); Alaska v. Arctic Maid, 366 U.S. 199, 81 S.Ct. 929, 6 L.Ed.2d *546227 (1961); Hope Natural Gas Co. v. Hall, 274 U.S. 284, 47 S.Ct. 639, 71 L.Ed. 1049 (1927). This is true even though the severed product is destined for immediate entry into interstate commerce, Arctic Maid, 366 U.S. at 204, 81 S.Ct. at 932; Oliver Iron Mining Co., 262 U.S. at 177-78, 43 S.Ct. at 529, and even though the cost of interstate commerce is increased. Coverdale v. Arkansas-Louisiana Pipe Line Co., 303 U.S. 604, 612, 58 S.Ct. 736, 740, 82 L.Ed. 1043 (1938). See Complete Auto Transit, Inc. v. Brady, 430 U.S. 274, 288, 97 S.Ct. 1076, 1083, 51 L.Ed.2d 326 (1977). The Tribe’s tax fits within this line of cases.
The clear thrust of the ordinance is that the taxable event is severance or bringing the resources to the surface. To be sure, the ordinance’s phrase “severed, saved and removed from Tribal lands” is ambiguous, for the taxable event could be removal from the territorial boundaries of the reservation after severance. But we think the phrase “remove from Tribal lands” merely means removal from the soil, as the Tribe argues. This interpretation is reinforced by the explicit requirement that the taxes are due at the time of severance. Nor does the provision that the tax rate is to be applied to oil or gas “sold or transported off the Reservation,” alter this conclusion. Although this phrase is also ambiguous, it would seem to mean the tax rate is applied to natural gas and oil that is sold on the reservation or transported off the reservation before sale. The only products not included in the tax computation are those used by the operators in the process of production and those received by the Tribe as royalty in kind. All other products are taxed at the time of severance.
The trial court also held the tax invalid as a multiple burden on interstate commerce, apparently because New Mexico imposes an oil and gas severance tax, as well as an oil and gas emergency school tax, an oil and gas conservation tax, and an oil and gas production equipment ad valorem tax. See N.M.Stat.Ann. §§ 7-29-1 to 7-29-22; id. §§ 7-31-1 to 7-31-25; id. §§ 7-30-1 to 7-30-26; id. §§ 7-34-1 to 7-34-20 (1978). The Supreme Court, in Western Live Stock v. Bureau, 303 U.S. 250, 58 S.Ct. 546, 82 L.Ed. 823 (1938), explained the basis for finding this type of violation of the Commerce Clause as follows:
The vice characteristic of [local taxes] which have been held invalid is that they have placed on the commerce burdens of such a nature as to be capable, in point of substance, of being imposed ... or added to . with equal right by every state which the commerce touches, merely because interstate commerce is being done, so that without the protection of the commerce clause it would bear cumulative burdens not imposed on local commerce.
Id. at 255-56, 58 S.Ct. at 548^49 (citations omitted) (emphasis added). Applying this analysis, we hold the trial court erred.
We first note that the focus is upon the type of tax that every state may impose with equal right. It is beyond question that no state, with the exception of New Mexico, has a sufficient connection with the occupation of severing oil and natural gas within the reservation to support levy of a severance tax on lessees’ occupation. There is thus no threat of a multiple burden emanating from this tax unless the possibility, which we assume is fact, of New Mexico levying an identical tax constitutes a multiple burden within the meaning of the Commerce Clause. That New Mexico may be able to impose an identical tax on lessees does not implicate the federal interest in maintaining the flow of interstate commerce at all, we believe. Rather it raises two different questions — whether the state’s tax interferes with the federal interest in regulating the affairs of the Indians, a question we do not reach, and whether a Congressional grant of authority to levy the state tax preempts tribal taxation, addressed in Part IV, infra.
We hold the federal interest in interstate commerce, manifested in traditional Commerce Clause analyses, does not limit the Tribe’s power to impose this tax.
IV
We next consider whether Congress has preempted the exercise of the Tribe’s *547power to levy the severance tax. The trial court held that by granting to the states the right to tax the production of oil and gas on executive order reservations, Congress intended to preempt similar tribal taxation. The basis of this ruling is 25 U.S.C. § 398c, which provides:
Taxes may be levied and collected by the State or local authority upon improvements, output of mines or oil and gas wells, or other rights, property, or assets of any lessee upon lands within Executive order Indian reservations in the same manner as such taxes are otherwise levied and collected, and such taxes may be levied against the share obtained for the Indians as bonuses, rentals, and royalties, and the Secretary of the Interi- or is hereby authorized and directed to cause such taxes to be paid out of the tribal funds in the Treasury: Provided, That such taxes shall not become a lien or charge of any kind against the land or other property of such Indians.
(Emphasis in original). Section 398c was an integral element of the Act of March 3, 1927, ch. 299, 44 Stat. 1347, which also settled then unresolved questions concerning the status of Indian mineral rights in executive order reservation lands and granted to the Indians all the royalty, rental and bonus income from oil and gas leases on their reservations. See id. § 2, 44 Stat. 1347 (codified at 25 U.S.C. § 398b). See also Sen.Rep.No.768, 69th Cong., 1st Sess. (1926); H.R.Rep.No.763, 69th Cong., 1st Sess. (1926).
In construing this statute, we must apply the
“eminently sound and vital canon,” Northern Cheyenne Tribe v. Hollowbreast, 425 U.S. 649, 655 n. 7 [, 96 S.Ct. 1793, 1797, 48 L.Ed.2d 274] (1976), that “statutes passed for the benefit of dependent Indian tribes ... are to be liberally construed, doubtful expressions being resolved in favor of the Indians.” Alaska Pacific Fisheries v. United States, 248 U.S. 78, 89 [, 39 S.Ct. 40, 42, 63 L.Ed. 138] (1918). See Choate v. Trapp, 224 U.S. 665, 675 [, 32 S.Ct. 565, 569, 56 L.Ed. 941] (1912); Antoine v. Washington, 420 U.S. 194, 199-200 [, 95 S.Ct. 944, 948-949, 43 L.Ed.2d 129] (1975).
Bryan v. Itasca County, 426 U.S. 373, 392, 96 S.Ct. 2102, 2112, 48 L.Ed.2d 710 (1976). Fairly read, this statute does not by its terms preclude tribal taxation of lessees engaged in the business of producing oil and gas from within executive order reservations. Moreover, the legislative history, which reflects Congress’s awareness of the need at that time for express authorization of state taxation of Indians and of non-Indians doing business with Indians on the reservation, does not show an express or implied intent to preempt tribal taxation. See H.R.Rep.No.1791, 69th Cong., 2d Sess. 4 (1927); Sen.Rep.No.768, 69th Cong., 1st Sess. (1926); H.R.Rep.No.763, 69th Cong., 1st Sess. (1926); 68 Cong.Rec. 4569-81 (1927); 67 Cong.Rec. 10912-25 (1926); 66 Cong.Rec. 2233-34 (1925); 66 Cong.Rec. 998-99 (1924).
A careful reading of the legislative history convinces us that Congress simply did not think of the issue when it enacted the statute, even though the Supreme Court and the Eighth Circuit had approved tribal taxation of nonmembers under similar circumstances. See Part II, supra. There was dispute over whether the Indians should receive all of the royalty income from leases of reservation lands. Legislators who opposed the Act as too generous might well have voted against giving the Indian tribes power to levy taxes, but the majority, who obviously thought that all benefits from the minerals on the reservations belonged to the Indians, might well have voted the other way. At no time when the state taxes were mentioned was there any discussion that the amount of such taxes might be relevant to passage of the Act. We therefore conclude that section 398c, being part of an act passed to benefit the Indians and ambiguous in letter and intent with respect to tribal taxation, does not preempt the tribal tax ordinance at issue in this case.5
*548It also may be argued that by virtue of its regulation of the leasing process, Congress preempted independent tribal taxation of those acquiring leases by that process. Cf. Warren Trading Post v. Arizona Tax Comm’n, 380 U.S. 685, 85 S.Ct. 1242,14 L.Ed.2d 165 (1965) (all-inclusive federal regulations and statutes applicable to trading on the reservations with Indians preempt state taxation of traders doing business thereunder). In essence, the argument is that by prescribing the procedures for the acquisition of leases and determining the royalty, bonus and rental payments the Indians are to receive, Congress intended that no burdens other than those embodied in the leases be imposed on the lessees.
When Congress first authorized leasing of land within executive order reservations for oil and gas purposes in the Act of March 3, 1927, ch. 299, § 1, 44 Stat. 1347 (codified at 25 U.S.C. § 398a), it provided that the same rules apply as for leasing oil and gas interests on other types of reservations. See 25 U.S.C. §§ 397, 398. Thus, the Secretary of the Interior, with the consent of the tribal council, was charged with the responsibility of conductings public auction to obtain the best terms possible for the Indians. See 25 U.S.C. § 398. But in 1938 Congress effected a change in this scheme that is significant for our purposes. The General Leasing Act of 1938, ch. 198, 52 Stat. 347 (codified at 25 U.S.C. §§ 396a-396g), intended to make uniform the various laws applicable to the leasing of Indian lands for mining purposes and to conform the laws to the purposes of the Indian Reorganization Act of 1934, §§ 16, 17, 25 U.S.C. §§ 476, 477. See H.R.Rep.No.1872, 75th Cong., 3d Sess. (1938). Therefore, it elaborated on the procedures to be followed for leasing oil and gas interests. But of greater significance is the proviso found in that section, which allows tribes organized and incorporated under 25 U.S.C. §§ 476, 477 to assume and define for themselves the leasing process.6
Thus, Congress expressly provided that tribes like the Jicarilla Apache Tribe may, by proper constitutional and legislative means approved by the Secretary of the Interior, see 25 U.S.C. § 476, determine the terms upon which they will lease their lands and regulate the operations of their lessees.7 Under these circumstances we can*549not conclude that Congress intended to so occupy the field of regulating leasing of tribal property for oil and gas leases that the Tribes could not impose additional burdens on lessees through exercise of the power of taxation.
The leases themselves contain a provision that no change may be made in the rate of “royalty or annual rental” without written consent of the parties to the lease. But as lessees acknowledged at oral argument, such a provision does not preclude a sovereign that is also a lessor from imposing a tax which has the practical effect of in-, creasing its revenues. It is well settled that such an agreement does not prevent the exaction of a license tax “unless this right has been specifically surrendered in terms which admit of no other reasonable interpretation.” City of St. Louis v. United Rys. Co., 210 U.S. 266, 280, 28 S.Ct. 630, 634, 52 L.Ed. 1054 (1908). See also New Orleans City & Lake R. R. v. City of New Orleans, 143 U.S. 192, 12 S.Ct. 406, 36 L.Ed. 121 (1892).
We have considered the remaining contentions of the parties and do not find them to be dispositive.
The judgment of the trial court is reversed and remanded with direction to enter judgment in favor of appellants.
. In one of the essentially identical cases Gwendolyn Velarde, Treasurer of the Tribe, and Tony Martinez, Executive Director of the New Mexico Oil and Gas Accounting Commission, were named as individual defendants. Prior to trial Martinez was dismissed from the suit without prejudice.
. The pretrial order recites that the Tribe, pursuant to a resolution of its Council, “waived any claim to sovereign immunity for the determination of the legal validity of this tax.” No question of immunity of the Tribe from suit was raised until it filed a reply brief in this Court.
. Even were we to conclude the ordinance did not constitute effective consent, it is clear that the court properly reached the merits in one of the cases consolidated for trial. Plaintiffs *541Amoco Production Company and Marathon Oil Company, in addition to naming the Tribe and Tribal Council as defendants, sued individually the tribal official charged with the enforcement and collection of the tax. The Tribe’s immunity from suit does not extend to tribal officials; therefore the trial court properly heard this case. Santa Clara Pueblo v. Martinez, 436 U.S. 49, 59, 98 S.Ct. 1670, 1677, 56 L.Ed.2d 106 (1978).
. The Stevedoring case, building upon Complete Auto Transit eliminated the distinction between direct and indirect taxation of interstate commerce when the tax is measured by gross proceeds. 435 U.S. at 743-51, 98 S.Ct. at 1395-1400. With that distinction fell the per se rule forbidding taxation of interstate commerce. Id.-, 430 U.S. at 287-89, 97 S.Ct. at 1083-84. A tax falling within the ambit of these cases is valid if it “is applied to an activity with a substantial nexus with the taxing State, is fairly apportioned, does not discriminate against interstate commerce, and is fairly related to the services provided by the State.” 430 U.S. at 279, 97 S.Ct. at 1079. See id. at 287, 97 S.Ct. at 1083; 435 U.S. at 750-51, 98 S.Ct. at 1399-1400. We need not decide whether a severance tax measured by quantity produced within a single jurisdiction falls within the ambit of this new doctrine. Obviously the questioned tax falls on activity — production — with a substantial nexus with the reservation. The tax does not raise the apportionment problem because it is measured by quantity, and as we have determined, it does not discriminate against interstate commerce. If the Stevedoring and Complete Auto Transit analysis applied, the only question is whether the tax is fairly related to services provided by the reservation. Lessees did not build a factual foundation in the record to challenge the tax on this ground, since they relied upon the rejected per se rule. Thus there is no basis on which to hold the tax invalid on this ground. See 435 U.S. at 750-51, 98 S.Ct. at 1399-1400.
. The Tribe also argues that New Mexico has no power to levy its severance tax on production within the reservation. Its argument in essence is that the General Leasing Act of *5481938, ch. 198, 52 Stat. 347 (codified at 25 U.S.C. §§ 396a-396g), which makes uniform the laws applicable to leasing of mineral rights on Indian reservations, and does not contain a specific grant of power to the states comparable to that found in the Act of March 3, 1927, ch. 299, § 3, 44 Stat. 1347 (codified at 25 U.S.C. § 398c), repealed the latter provision. See § 7, 52 Stat. 347. Because the State of New Mexico is not a party to this litigation and we hold the State’s power to tax, if any, is not exclusive, we do not reach this question. For the same reasons we do not address the Tribe’s contention that the trial court erred in not allowing the Tribe to put the leases into evidence to show whether they were granted under § 398c or under § 396a.
. 25 U.S.C. § 396b provides:
Leases for oil- and/or gas-mining purposes covering such unallotted lands shall be offered for sale to the highest responsible qualified bidder, at public auction or on sealed bids, after notice and advertisement, upon such terms and subject to such conditions as the Secretary of the Interior may prescribe. Such advertisement shall reserve to the Secretary of the Interior the right to reject all bids whenever in his judgment the interest of the Indians will be served by so doing, and if no satisfactory bid is received, or the accepted bidder fails to complete the lease, or the Secretary of the Interior shall determine that it is unwise in the interest of the Indians to accept the highest bid, said Secretary may readvertise such lease for sale, or with the consent of the tribal council or other governing tribal authorities, a lease may be made by private negotiations: Provided, That the foregoing provisions shall in no manner restrict the right of tribes organized and incorporated under sections 476 and 477 of this title, to lease lands for mining purposes as therein provided and in accordance with the provisions of any constitution and charter adopted by any Indian tribe pursuant to sections 461, 462, 463, 464-475, 476-478, and 479 of this title.
(Emphasis added).
. The Secretary of the Interior has implemented by regulation the substance of the proviso as follows:
The regulations in this part may be superseded by the provisions of any tribal constitution, bylaw or charter issued pursuant to the Indian Reorganization Act of June 18, 1934 (48 Stat. 984; 25 U.S.C. §§ 461-479), or by ordinance, resolution or other action authorized under such constitution, bylaw or charter. The regulations in this *549part, in so far as they are not so superseded, shall apply to leases made by organized tribes if the validity of the lease depends upon the approval of the Secretary of the Interior.
25 C.F.R. § 171.29 (1979).