 Historical records indicate that Chinook salmon ("Oncorhynchus tshawytscha") occurred in at least two San Francisco Bay Area watersheds, San Leandro Creek in Alameda County, and San Mateo Creek in San Mateo County.In the 1870s, “quinnant”, or Chinook salmon were reported from lower San Leandro Creek and persisted in Lake Chabot for several years following the completion of Lake Chabot Dam in 1875.California Department of Fish and Game Warden George Smalley reported runs of coho salmon ("Oncorhynchus kisutch") and steelhead trout ("Oncorhynchus mykiss irideus") in San Leandro Creek “…in the
early days” and “…that after the completion of the Upper San Leandro Reservoir a run still persisted to the base of the dam for many years”.