Close to the city, iconic views, and a few challenging hills with an isolated beach - the Marin Headlands, even though it lacks significant singletrack, is your best dirt this side of Mount Tam.
Most of the trails are well-signed except for where the Coastal Trail runs along Bunker Road and connects with Rodeo Valley Trail
. Summers can get foggy with fall and spring being the best weather. The trails or fire roads hold up well in wet weather. There is a 15 mph speed limit, and many of the other trails in the park are not legal for mountain bike use, so please follow the designated route.
This ride starts at the north end of the Golden Gate Bridge. The ride can also be started from the city side, just cross the bridge on the bike path (west side). For visitors, bikes can be rented at many locations in the city. Sports Basement is located in the Presidio at the base of the bridge. A light hardtail 29er is perfect.
If you're a local yokel and don't want to ride up the paved road from the bridge, there's parking at the Coastal Trail trailhead at the traffic roundabout off McCullough Road.
From the parking lot, paved Conzelman Road climbs up the hill to Battery Spencer where you're practically on top of the Golden Gate Bridge with expansive views of the city and the Bay. Continue up for about a mile to the traffic circle mentioned above. Ride past the restroom through the parking area to the Coastal Trail. This section of the Coastal Trail is a smooth downhill run all the way to Bunker Road and the junction with the Rodeo Valley Trail
. The only obstacles are a few water bars as it gets steeper near the bottom. Keep left and follow paved Bunker Road a short distance to the horse stables, and the trail will be to the right. Cross the wooden bridge then left take a left on Rodeo Valley Trail
, then left again on Bobcat Trail
. Bobcat ends at the Miwok (South) Trail. Turn right to start the obvious climb.
This section of Miwok is the first and most challenging climb. It's smooth, wide, and the gradient isn't too bad at the start, but it doesn't let off and gradually gets steeper - just keep plugging for a mile and a half to the top of Wolf Ridge. After leveling off, it looks like it gets very steep but this is where you turn off onto Old Springs Trail
Old Springs Trail
is the closest thing to singletrack you'll find in this area. From Miwok, it's a downhill run all the way to the Tennessee Valley trailhead. You'll cross several wood bridges and it starts off fairly smooth with nice views down Tennessee Valley to the Pacific Ocean. It gets steeper and more rutted as it drops off the ridge with some wood "steps,"rock drains, and a few switchbacks to make things interesting. It's over too soon in a little over a mile as you reach another horse stable and the trailhead.
Continue down the Tennessee Valley Trail
to the beach in a couple miles. Retracing back to the trailhead, you'll find the Marincello Trail
past a gate on the east side of the parking area. Like Miwok, it's a steady climb on a smooth fire road for nearly two miles where it joins the Bobcat Trail
At the top of the Bobcat Trail
, you'll catch glimpses of the city and the Bridge but it drops quickly into the Gerbode Valley in sweeping and a few tight turns. In a couple miles, you'll reach the junction with Rodeo Valley Trail
on the left (watch for the steps) and at this point you'll be retracing your way back and up the Coastal Trail and down to the parking area (or to the city).
Marin Headlands was a military installation (Fort Barry and Fort Baker) protecting the entrance to San Francisco Bay which, in turn, protected the landscape until the area became a park.