This research focuses on two elements of contemporary American Indian natural resource management. First, the authors explore the capacity of tribes to manage natural resources, including the merging of traditional ecological knowledge (TEK) with Western science. Second, they analyze tribal management in the context of local and regional collaborative watershed groups. Of particular interest to this discussion is the variation in the capacity of individual tribes to participate actively in resource management. The authors compare three cases--two from the Pacific Northwest, namely, Jamestown S'Klallam Tribe and Confederated Tribes of the Umatilla Indian Reservation, and one from the Southwest, namely, Yavapai-Apache Nation--to explore the challenges tribes face to regain partial or complete control of traditional lands and resources. The three cases illustrate that there is not a clear divide between the use of Indigenous knowledge and Western science in tribal resource management. All three tribes in this case study rely heavily upon Western-trained managers and scientists while at the same time tribal values frame how the Western science is interpreted and implemented. Combining TEK and Western science provides a powerful mechanism for resource management in the twenty-first century. The authors find broad differences in tribal capacities and conclude that developing tribal resources for management is a prerequisite for successful collaborative watershed management. (Contains 71 notes.)