If you prefer two wheels to two feet, you’ll find the road and trail biking in the Marin Headlands [1] both plentiful and spectacular. From the Tennessee Valley Trailhead, you’ll find plenty of multi-use trails designated for bikers as well as hikers.
The Valley Trail (4 mi round-trip) takes you down the Tennessee Valley and all the way out to Tennessee Beach. A longer ride runs up the Miwok Trail (2 mi) northward. Turn southwest onto the Coyote Ridge Trail (0.9 mi), then catch the Coastal Fire Road (2 mi) the rest of the way west to Muir Beach [2].
Another fun ride leads from just off U.S. 101 at the Rodeo Avenue exit. Park your car on the side of Rodeo Avenue, then bike down the Bobcat Trail (2.5 mi) straight through the Headlands to the Miwok Trail for just 0.5 mile, and you’ll find yourself out at Rodeo Beach.
Need to rent a bike for your travels? In San Francisco [3], Bike and Roll (899 Columbus Ave., 415/771-8735, www.bikerental.com [4], daily 8 a.m.–10 p.m. in summer, until 6 p.m. in winter) offers off-road biking tours of the Marin Headlands [1], plus bike rentals that let you go wherever the spirit moves you.
Links:
[1] http://www.moon.com/destinations/california/san-francisco-and-the-bay-area/north-bay/marin-headlands
[2] http://www.moon.com/destinations/california/san-francisco-and-the-bay-area/north-bay/marin-headlands/muir-beach
[3] http://www.moon.com/destinations/california/san-francisco-and-the-bay-area
[4] http://www.bikerental.com