Southern Steelhead trout (Oncorhynchus mykiss) are thought to represent about 1% of the historic population and most of the Santa Maria River run is thought to have continued up the Sisquoc River to spawn. Major dams on the Santa Ynez, Ventura, and Santa Clara Rivers prevent steelhead from accessing hundreds of miles of habitat and have drastically reduced the steelhead runs.
Southern Steelhead trout (Oncorhynchus mykiss) are believed to represent a small portion of the historical population, and most of the Santa Maria River run is thought to have continued up the Sisquoc River. Major barriers posed by dams on the Santa Ynez, Ventura, and Santa Clara Rivers restrict Steelhead access to their natural habitat, leading to significant declines in their runs.