Cotton Petroleum Corporation v. New Mexico

The Jicarilla Apache Tribe already taxed Cotton's (plaintiff's) on-reservation oil and gas production at 8 percent under a tax the Supreme Court had separately upheld, and New Mexico (defendant) also imposed its own state tax on that same production; Cotton challenged the state tax as preempted by the federal Indian Mineral Leasing Act, and the Tribe intervened arguing the state tax discouraged companies from working on the reservation and reduced tribal revenues.