Attention has turned in the past 30 years to the situation of Indigenous Peoples in National Parks and protected areas worldwide. Their position brings historical problems, as well as new opportunities, for applied ethnobiology to contribute to cooperative management situations that could help rectify past injustices. In the mid-1990s, the Timbisha Shoshone Tribe began a struggle for land within and surrounding Death Valley National Park, California. This was capped by the passage of the Timbisha Shoshone Homeland Act in 2000. It granted the Tribe trust lands and the right to co-manage additional lands held by the National Park Service and the Bureau of Land Management. Ethnobiology was used during negotiations to document the extent and uses of Timbisha traditional lands through ethnobotanical, ethnozoological, traditional resource and environmental management (TREM), and place name studies. The Tribe then initiated a pilot project in applied ethnobiology to bring TREM back to their lands through a honey mesquite (Prosopis glandulosa) and singleleaf pinyon pine (Pinus monophylla) management project, designed to demonstrate to the agencies the value of traditional care practices. The project was in place for two years when problems arose that could not be easily resolved. This case study outlines some of the procedures used and the problems encountered. It also illustrates the value of the project, as well as some of the frustrations that can occur during the course of an applied ethnobiology project.