Each year Native American tribal nations enter hundreds of federal contracts worth billions of dollars to run federal Indian programs. By substituting tribal governments for federal agencies, these “self-determination contracts” have been enormously successful in improving the effective delivery of federal programs in Indian country. However, tribal governments wish to do more. Tribes wish to co-manage federal public lands, including lands that lie outside their reservations, and they have a lot to offer in this area. For example, a tribe might seek to contract with the Fish & Wildlife Service to operate a wildlife refuge, or with the National Park Service to manage a park or monument or even with the Bureau of Reclamation to operate a federal dam. Tribes are natural partners for much of this work. Many federal units are located on lands that are, or were, tribal aboriginal lands. Although the federal government has had the legal authority to enter such contracts since 1994, federal agencies have been slow to enlist tribes in the management of federal public lands. A review of the few existing successful cases suggests that tribes confront dramatically different dynamics when seeking to contract functions with agencies beyond the Bureau of Indian Affairs or Indian Health Service and other agencies providing services to Indian people. At a time when indigenous-led conservation is crucial to addressing climate change and our national conservation goals, this article examines the obstacles to tribal co-management of public lands and proposes solutions.