Mountain Biking activities in Marin County
Bikers must stay on fire roads (and off the single-track trails) and keep speeds under 15mph. The rangers take these rules seriously, and a ticket can result in a steep fine.
The most popular ride is the Old Railroad Grade. For a sweaty, 6-mile, 2280ft climb, start in Mill Valley at the end of W Blithedale Ave and bike up to East Peak. It takes about an hour to reach the West Point Inn from Mill Valley. For an easier start, begin partway up at the Mountain Home Inn and follow the Gravity Car Grade to the Old Railroad Grade and the West Point Inn. From the Inn, it's an easy half-hour ride to the summit.
From just west of Pantoll Station, bikers can either take the Deer Park…
The headlands have some excellent mountain-biking routes, and there is no more exhilarating ride than the trip across the Golden Gate Bridge to reach them.
For a good 12-mile dirt loop, take the Coastal Trail west from the fork of Conzelman and McCullough Rds, bumping and winding down to Bunker Rd where it meets Bobcat Trail which joins Marincello Trail and descends steeply into the Tennessee Valley parking area. The Old Springs Trail and the Miwok Trail take you back to Bunker Rd a bit more gently than the Bobcat Trail, though any attempt to avoid at least a couple of hefty climbs on this ride is futile.