According to local historian Dorothy Regnery's notes from her 1966 interview with Edgar H. Batchelder, who was 2 years old when his father became caretaker of Searsville Dam in 1897, "When the dam was 'wasting', or overflowing in the winter, salmon would swim upstream as far as the base of the dam.
Several lines of evidence support the historical presence of coho salmon (Oncorhynchus kisutch) in San Francisquito Creek.