Species: Lampetra richardsoni

F - 20,000-200,000 square km (about 8000-80,000 square miles) - F - Range includes streams of the North American Pacific coast from Taku River, southern Alaska, to central California, including Vancouver Island, with major inland distributions in the Columbia and Sacramento-San Joaquin drainages (Vladykov and Follett 1965, Moyle 2002, Wydoski and Whitney 2003, Page and Burr 2011). In Washington, this species occurs in coastal and Puget Sound streams and as far inland as the upper reaches of the Yakima River; recorded in streams on the west and south sides of the Olympic Peninsula but not on the north or east sides (Wydoski and Whitney 2003). This lamprey is relatively common in forested coastal basins, such as the Alsea River, Oregon, but has largely disappeared from Columbia River basins above Bonneville Dam. In California, western brook lampreys have been recorded mainly from the Sacramento River drainage, including areas as remote as Kelsey Creek above Clear Lake (Lake County), but they are also present above Pillbury Reservoir in the Eel River and in Mark West Creek, a tributary of the Russian River; spawning adults were collected in the Navarro River (Mendocino County) in 1999 (Moyle 2002). Ammocoetes from an extirpated population in the Los Angeles River basin may represent this species (Moyle 2002). Western brook lamprey is easily overlooked and difficult to collect, it is likely that this species occurs in many streams in coastal California (Moyle 2002).