Coho salmon
As of 2000, Atascadero Creek and its major tributaries supported steelhead trout and California freshwater shrimp. The Atascadero is also historic spawning habitat for threatened steelhead salmon (oncorhynchus mykiss) and endangered coho salmon (oncorhynchus kisutch). Coho salmon are listed among the top ten endangered species under the federal Endangered Species Act. In 2001 a captive breeding program was established below Warm Springs Dam to restore their dwindling population.