Abstract: In the wake of a December 2014 decision by the Department of Justice to deprioritize enforcement of federal marijuana laws against tribes as well as states, many tribes have reevaluated their policies toward marijuana. Tribal attitudes toward marijuana are diverse; some tribes regard marijuana as a public health menace, whereas others see it as a source of economic opportunity. Where tribal policies are significantly more or less restrictive than those of the surrounding state, tribal-state relations have often suffered friction. The problem is particularly acute given the jurisdictional uncertainty that characterizes Indian country and the absence of any equivalent to the conflict-mediating doctrines that help to smooth interstate relations. As a result, federal intervention may be needed to protect tribal sovereignty and resolve tribal-state conflict; any such action should be guided by recognizing the successes and failures of the Indian Gaming Regulatory Act.