The Pacific Lamprey (Entosphenus tridentatus) was historically widespread along the West Coast of the United States but populations have declined in abundance and become restricted in distribution throughout California, Oregon, Washington, and Idaho. Threats to Pacific Lamprey may include dams, stream degradation, poor water quality and impacts of climate change, and these occur throughout the range of the species. The U.S. Fish and Wildlife Service recognizes the need for a comprehensive plan to conserve and restore Pacific Lamprey in collaboration with Native American tribes and other Federal, State, and local agencies. The Pacific Lamprey Conservation Initiative is the U.S. Fish and Wildlife Service's strategy to improve the status of Pacific Lamprey throughout their range by helping implement research and conservation actions.