Bay Area Coho Salmon:

The early 1980s was the last time a coho salmon was sighted in the San Francisco Bay Area.

CEMAR has completed an analysis of the historical status of coho salmon in
the streams of the San Francisco Estuary that has recently been published.
The information in this paper was used by the California Department of Fish
and Game in preparing the Endangered Species Act listing petition for coho
salmon in California. The paper also documents likely causes of the species'
extirpation from the Bay Area, serving both as a cautionary note and
guidance for those interested in maintaining habitat for steelhead in the
region. The paper can be downloaded here.

The paper should be cited as: Leidy, R.A., G. Becker, and B.N. Harvey. 2005.
Historical Status of Coho Salmon in Streams if the Urbanized San Francisco
Estuary, California. California Fish and Game 91(4): 219-254.