 Justice Thurgood Marshall delivered the opinion of the court . Marshall noted that the tribe had a properly formed constitution , approved by the Secretary of the Interior , and that it included that the tribal council may impose taxes on non @-@ members doing business on the reservation . He noted that the tribe had executed oil and gas leases for about 69 % of the reservation and that the leases provided for royalties to be paid to the tribe . Marshall further noted that the tribe followed the proper process to enact a severance tax , obtaining the approval of the BIA as part of the process . The first argument of the oil companies that the power to tax only arose from the power of the tribe to exclude persons from the reservation . Marshall disagreed , stating that the power to tax is an inherent attribute of a tribe 's sovereignty . Tribal government includes the need to provide for services , not only to the tribe , but to anyone doing business on the reservation . He noted that the oil companies benefited from police protection and other governmental services . Citing Colville , he stated that the tribe 's interest in raising " revenues for essential governmental programs . . . is strongest when the revenues are derived from value generated on the reservation by activities involving the Tribes and when the taxpayer is the recipient of tribal services . " Marshall noted that Congress was able to remove this power , but had not done so , and had acknowledged in 1879 the power of the Cherokee Nation to tax non @-@ Indians . 
