Power relations among cultural, socio-economic, and political groups have been dynamic forces shaping American history. Within that changing world, relations between indigenous and non-indigenous groups have been complicated by a fundamental difference often ascribed to Western philosophy versus Native American spiritual traditions. In 1990, Congress codified that difference when it passed the Native American Graves Protection and Repatriation Act (NAGPRA) stipulating that Indian tribes and Native Hawaiians are unique among United States cultural groups. At the same time, NAGPRA began breaking down the Western vs. indigenous paradigm. The legislative process of NAGPRA strongly encouraged cooperation among indigenous peoples and the non-indigenous peoples who had collected their bones and belongings under earlier policies. NAGPRA required museums and other agencies accepting federal monies to inventory any collections of Native American items with the intent of giving control to tribes over the disposition of culturally affiliated human remains and certain classes of objects. In the rearranging power relations NAGPRA instigated, people maneuvered for power over the "truth," over whose memory, meaning, and spiritual worldview held authenticity. This dissertation considers cases that pushed or broke the limits of cooperation fostered by NAGPRA. Ignoring the bones and related funerary objects, Tangled Truths analyzes repatriation disputes over cultural artifacts to illuminate changing power relations among cultural groups in the United States. The repatriation negotiations in which people would not compromise were cases in which there existed strong differences in spiritual worldviews, cultural memories, or material interests. Congress could encourage cooperation, but it could not legislate acceptance of others' spiritual worldviews, nor could it persuade people to relinquish engrained cultural memories. And without solid enforcement, the NAGPRA process could be outmaneuvered by those intent on pursuing their own material interests.