Crystal Springs Reservoir is located about 20 miles south of San Francisco and serves both as water reserve and recreational area for Silicon Valley dwellers. The paved path alongside its eastern shore is open to both pedestrians and bicyclists.

The southern part of this so-called Sawyers Camp Trail starts at Crystal Springs Rd 280 exit and extends 6 miles to the North, passes the dam at the south end of San Andreas Lake, and ends at the Hillcrest Blvd 280 exit.

The trail is fenced off all the way, both to the water and to the 280 side, so walking it 6 miles one way gets somewhat long in the tooth, but riding it on a bike is a breeze. The small dam at San Andreas Lake is quite scenic, the trail continues from here north for another 2 miles, but it's a dead end (except a 280 exit and a footpath further north), so it's best to turn around from there and head back.