North Pacific: Bering Sea coasts of Asia and Alaska southward to the Yuhutu River, Hokkaido, northern Japan and Punta Canoas, central Baja California, Mexico. The populations were, at one time, split into two groups (Ref. 10015) as Entosphenus tridentatus tridentatus which ranged from the Columbia River to Alaska, and Entosphenus tridentatus ciliatus which ranged from Klamath River southwards (Ref. 1998). This division no longer holds (Ref. 1998). Freshwater resident populations exist in Culrus Lake and the Columbia River, British Columbia, the Sprague River in Oregon, the Goose Lake in Oregon/California, and the Klamath and Shasta rivers and Copco Lake in California (Ref. 12269).