March 13, 1806, at Fort Clatsop, Oregon.

Elongate, fusiform. Marine coloration: metallic-blue above, silvery-white below, with small, black spots on back, sides, and dorsal and caudal fins. Freshwater coloration: spots more prominent, distinctive red band on sides. Length: to 3.8 ft (1.1 m). Weight: 42.1 lbs (19.1 kg).

Inshore ocean at mid-depths and near surface; spawns in freshwater streams and rivers.

From Bering Sea to southern California. In fresh water, native range confined to lakes and streams of western states bordering Pacific Ocean from Alaska to Baja California; introduced throughout Canada and United States in suitable streams and lakes.

Sea-run populations of the rainbow trout, known as steelheads, are on the U.S. Endangered Species List.