Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Adults migrate up streams typically in late summer and fall (late fall through mid-winter in the far south), when heavy fall rains result in flows strong enough to breach sand bars at the mouths of coastal streams (Moyle et al. 1989).. Some populations, now considered extinct, may have migrated hundreds of miles inland to spawn in tributaries of the upper Columbia River in Washington and the Snake River in Idaho (NMFS 1995).
See NMFS (1995) for information on the oceanic distributions of the different spawning stocks in Washington, Oregon, and California.
In California, "big river coho salmon" begin entering streams typically in September or October, migrate upstream 100-200 km or more to spawning sites; "short-run coho salmon" rarely migrate more than 100 km upstream (Moyle et al. 1989). In California, juveniles begin migration downstream to ocean in early spring; migrate in schools of 10-50 (Moyle et al. 1989).