This is the most challenging climb in Marin County and boasts an impressive 5.02 FIETS index, well above any other climb in the county. Beginning in the popular coastal town of Stinson Beach (provisions available at the Stinson Beach Market about a half mile to the north on Hwy 1 from the climb start point).
Mt. Tamalpais is the highest peak in the Marin County and has 2 peaks - the East Peak (2,574') and West Peak (2,563'). The white radar dome that sits upon Mt. Tam's slightly lower western peak is quite discernable from afar.
The climb is divided into 3 parts:
A very pleasant, and challenging, 46 mile route that captures the 2 top climbs in Marin County begins from the south end of the Golden Gate Bridge, across the Bridge, through Sausilito, Mill Valley, down to Muir Woods, back up to Panoramic Highway (follow Pano Hwy from its southern (intersection Muir Woods Rd and Panoramic Hwy to its northern point at Stinson Beach on Hwy 1 - 8.1 miles), up to the top of Mt. Tam and then follow the route back to San Francisco. See PJAMM Cycling’s Golden Gate Bridge Page and also its RideWithGPS map for more details.