It descends northward to Woodacre, where it turns westward and parallels Sir Francis Drake Boulevard through the villages of San Geronimo, Forest Knolls, and Lagunitas.

It then turns southwestward and joins Lagunitas Creek at the eastern edge of the Samuel P. Taylor State Park.

These coho are part of the "Central California Coast Evolutionarily Significant Unit," or CCC ESU, and are listed as "endangered" at both the state and federal level.

Efforts are also being made to protect and restore streams and habitat in the San Geronimo Valley, where upwards of 20% of the Lagunitas salmon spawn each year and where as much as 1/5 of the juvenile salmon (or fry) spend their entire freshwater lives.

[citation needed] Spawning salmon and trout may be viewed at Roy's Pools, located about 5 miles (8.0 km) west of Fairfax.