The San Lorenzo River starts at its headwaters above Boulder Creek, it runs through the valley on its way to the city of Santa Cruz, where it then flows into the Monterey Bay and the Pacific Ocean and also supplies the city of Santa Cruz with its drinking water. Much of the river valley is rural and wooded and other areas have neighborhoods and schools, and shopping areas. At its northern end, it abuts Big Basin Redwoods State Park and Castle Rock State Park; toward the southern end is Henry Cowell Redwoods State Park.[1]