Bill Williams River National Wildlife Refuge preserves the lower Bill Williams River in western Arizona where it meets Lake Havasu. In the Lower Colorado River Valley, this protected area brings river, marsh, and desert habitats together at the meeting point of the Mojave and Sonoran deserts, creating exceptional plant and animal diversity. Established in its present form in 1977 after The Nature Conservancy transferred the land to the U.S. Fish and Wildlife Service, it protects the largest remaining cottonwood-willow forest along the lower Colorado River. The refuge shelters endangered and native species, supports migratory birds, and also provides opportunities for low-impact outdoor recreation.