Coho salmon
The first recorded stream survey occurred in the year 1946; this survey by the California Department of Fish and Game found some healthy steelhead "(Oncorhynchus mykiss)" within the stream. The next Department of Fish and Game survey transpired in 1963, finding numerous steelhead of lengths varying between and ; this survey concluded that the lower of the creek represented an important nursery and rearing habitat for steelhead and possibly for Coho salmon. The next survey in August 1965 concluded that the habitat was an excellent resource, with deep shaded pools and an average of 75 steelhead per of lineal stream. In 1984, steelhead were still found to be present. A 1991 stream survey documented the historical presence of Coho salmon. The next survey in 1994 found abundant steelhead, ranging from densities of 0.1 to 0.6 fish per square yard (0.1-0.7 per square meter). The 1997 stream survey found densities of steelhead ranging from seven to twelve fish per 100 lineal feet (30 lineal meters), depending on stream reach. In its 2004 "Recovery Strategy for California Coho Salmon" the California Department of Fish and Game recommends restoration of Arroyo Corte Madera's historic coho salmon habitat. This is one of only two San Francisco Bay Area streams considered in the Department's Strategy to be essential to the recovery of coho salmon in California.