delivered the opinion of the Court.
Since each of the captioned cases involves the same subject matter, we decided the same together. Both of the appeals involve an attempt by the State of Montana to collect state income taxes on income earned by Indians living on an Indian reservation and derived solely from reservation sources. The District Court, Fifteenth Judicial District, Roosevelt County, concluded in each case that the State had jurisdiction to impose and collect state income tax from both appellants. For the reasons set forth below we reverse.
The facts in these two causes were stipulated:
William LaRoque is an enrolled member of the Turtle Mountain Chippewa Tribe, North Dakota, and his wife, Belva, is an enrolled member of the Assiniboine-Sioux Tribes of the Fort Peck Reservation, Montana. They lived in the Fort Peck Reservation during the year 1968 and several years before. In 1968, LaRoque earned money within the exterior boundaries of the Fort Peck Reservation, for which he paid income tax to the State. In this action he seeks a refund of that tax for the money he earned as an Indian on an Indian reservation.
Tony Boxer is a Chippewa Indian, born in North Dakota in 1912. His father was a Chippewa from the Red Lake Reservation, Minnesota and his mother was a Chippewa from the Turtle Mountain Reservation, North Dakota. Since 1921, Boxer has lived on the Fort Peck Reservation. Boxer owns an undivided .016 interest in a tract of land held in trust by the United States on the Fort Peck Reservation and income from that land is paid into Boxer’s Individ *318 ual Indian Money Account by the Bureau of Indian Affairs. The record indicates Boxer is entitled to medical treatment from the Indian Public Health Service and has a work preference as an Indian in the Indian Manpower programs on the Fort Peck Reservation. Although it is stipulated Boxer is a Chippewa Indian, he has never been formally enrolled in any tribe.
During the years 1967 and 1968, Boxer earned income within the Fort Peck Reservation other than that derived from his trust land, and the State is seeking to tax that income. In his action, Boxer seeks to enjoin that collection because he is an Indian and the income was earned on an Indian reservation.
These cases were decided on a stipulated record as set out above, and on crossmotions for summary judgment. In each case the District Court held the State had jurisdiction to tax the Indian income in question, since each was not a member of the Assiniboine-Sioux Tribe. The Court also said the holding of
McClanahan v. Arizona Tax Commission
(1973),
The issue presented for review is the same: whether an Indian not an enrolled member of the tribe on whose reservation he is living, may be taxed by the State for income earned on that reservation? We are not asked to decide, nor do we decide, questions concerning jurisdiction of the State in any situation other than that presented here. Preliminary to discussing the issue presented, we must determine whether the decision in McClanahan may be applied here or whether it is barred by the rule of nonretroactivity. McClanahan, if it may be applied and is not barred by nonretroactivity, will control the disposition of these appeals.
Respondents have contended that, because of their reliance on state statutes, appellants’ acquiescence in filing returns and the apparent applicability of the statutes to appellants, this Court should consider
McClanahan
to be nonretroactive in application. The United States Supreme Court in
Chevron Oil v. Huson
*319
(1971),
First, as was made plain in
Hanover Shoe v. United Shoe Machinery Corp.
(1968),
The second factor we must consider is whether the retroactive application of the rule of McClanahan in these appeals will retard or further the rule’s operation. It seems apparent to this Court if the McClanahan decision may be applied to these cases, our determination as to whether it can in fact be applied will resolve much doubt as to just who is to benefit from the principle of that case. Retroactive application here can thus only further the operation of the rule in McClanahan.
Finally, we must consider what inequities may result from a retroactive application. It is important to note it is respondents who must convince this Court that retroactive application would result in substantial inequitable results,
Jimenez v. Weinberger
(7th Cir. 1975),
We find the decision in McClanahan can be applied retroactively. Having decided application of McClanahan is not barred, we must now determine whether it in fact is applicable.
McClanahan
held in attempting to impose a state income
*321
tax on income earned by an on-reservation Indian derived solely from reservation sources, Arizona had “interfered with matters which the relevant treaty and statutes leave to the exclusive province of the Federal Government and the Indians themselves.” The tax was therefore “unlawful as applied to reservation Indians with income derived wholly from reservation sources.”
McClanahan,
“* * * [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. It follows that Indians and Indian property on an Indian reservation are not subject to state taxation except by virtue of express authority conferred upon the state by act of Congress.” Cohen, Handbook of Federal Indian Law at 254.
The United States Supreme Court has agreed that preemption analysis is particularly persuasive in the special area of state taxation:
“[A]bsent 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] lays to rest any doubt in this respect by holding that such taxation is not per *322 missible absent congressional consent.” Mescalero Apache Tribe v. Jones (1973),411 U.S., 148 ,93 S.Ct. 1267 , 1270,36 L.Ed.2d 114 .
We find from an examination of relevant statutes that such cession to Montana jurisdiction as to taxation has not occurred.
The Buck Act, 4 U.S.C. § 105 et seq., provides comprehensive guidance for state taxation of those persons living within federal areas. Section 106(a) of the Act gives to the state general authority to tax income of residents of federal areas but section 109 excepts “Indians not otherwise taxed” from this authority. The United States Supreme Court has interpreted this section and its legislative history as-referring to reservation Indians earning their income on the reservation.
McClanahan,
As our discussion above indicates state authority within the exterior boudaries of an Indian reservation is limited. See,
Fisher v. District Court
(1976),
Respondents contends appellants’ status as non-members of the Fort Peck Reservation Assiniboine-Sioux Tribes denies them the protection of
McClanahan.
We do not agree. As is clear from the comparison above, between state jurisdiction on and off the reservation, the primary factor in limiting state jurisdiction is whether the activity occurred in “areas set aside by treaty for the exclusive use and control of Indians.”
McClanahan,
We therefore, conclude that
situs
of the activity is the primary factor in determining whether state taxation jurisdiction exists, not the status of the individual as enrolled or non-enrolled. We read the phrase “reservation Indian” in
McClanahan
to mean Indians residing on the reservation, and not just Indians who are enrolled members of the tribe. We find support for this conclusion in
Fox v. Bureau of Revenue
(1975),
In the instant appeals we are faced with the same coalescence of situs and status that existed in the above cases and in
McClanahan.
Both appellants, LaRoque and Boxer, resided and earned the income which the State seeks to tax on the Fort Peck Reservation. Both appellants are Indians, a stipulated fact. Congress has not expressly ceded authority to Montana to tax income of on-reservation Indians nor has the State acted under available procedures to acquire such jurisdiction. Since both appellants are Indians residing on the reservation, and since each of their incomes were derived wholly from reservation sources, their activity is “totally within the sphere which the relevant treaty and statutes leave for the Federal Government and for the Indians themselves.”
McClanahan,
Respondents have suggested we follow the decision of the Minnesota Tax Court of Appeals in Topash v. Commissioner of Revenue, No. 2054 (Minn.Tax App.Ct., Dec. 3, 1976). We decline to do so. The Court there offers us no compelling reason as to why we should accept its restrictive reading of McClanahan, and in the face of the authority discussed above concerning tribal affiliation in jurisdictional questions, a mere statement that if the United States Supreme Court had meant all Indians, it would have said so, is not persuasive.
Having found
McClanahan v. Arizona Tax Commission
is retroactive in application, that it does apply to these appeals and therefore the State was without authority to impose the taxes here in question, we now consider how this decision is to be implemented with respect to these appellants. We first make clear the interests of the State in an orderly tax collection procedure mandate an adherence to the State’s procedure for refunds, Chapter 49, Title 84, 1947 Revised Codes of Montana. This is a procedural require
*326
ment only, and does not interfere in any way with appellants’ substantive right to be free from state authority to tax. Therefore, if LaRoque’s claim for refund is not barred by these procedures, it should be granted. Boxer, having never paid the tax, is not seeking a refund but rather is seeking to enjoin the state from collecting tax. Such an injunction should be granted. Plainly, to require Boxer to go through the refund procedure would subject him to state authority to collect the tax which we now hold invalid. The refund procedure implicitly presupposes the state can intrude on an Indian’s rights by collecting the tax before the remedy is made available. Since Boxer lacks an adequate remedy at law, equitable injunctive relief is necessary. Dobbs,
Law of Remedies,
§ 2.5. See,
Dillon v. State of Montana
(D.Mont.1978),
Reversed and remanded with directions to amend the judgments entered by the District Court to conform to this opinion.
