3.5
(3)
102
riders
14
rides
Gravel biking around San Geronimo California offers diverse landscapes within Marin County, featuring rolling hills, lush forests, and meandering creeks. The region is characterized by varied ecosystems, including oak woodlands and redwood forests, providing a range of natural settings. Prominent natural features like San Geronimo Ridge and Mt. Barnabe define the valley's terrain. The area is well-suited for gravel biking due to its extensive network of dirt roads, gravel paths, and fire roads.
Last updated: May 3, 2026
4.0
(2)
35
riders
65.9km
04:42
1,010m
1,010m
Hard gravel ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.
3.0
(1)
9
riders
38.6km
03:35
950m
940m
Hard gravel ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.

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9
riders
52.5km
05:00
1,510m
1,500m
Hard gravel ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.
5.0
(1)
14
riders
Hard gravel ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.
3
riders
15.9km
01:33
490m
500m
Hard gravel ride. Very good fitness required. Mostly paved surfaces. Suitable for all skill levels.
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An absolute must-see for cycling enthusiasts! This museum in Fairfax tells the story of nearly 200 years of cycling history, from 19th-century velocipedes to modern racing bikes. It's also home to the Mountain Bike Hall of Fame, featuring unique specimens and stories about the pioneers of mountain biking. The collection is impressive and authentic—no replicas, but real bicycles that showcase the evolution of technology and design. An inspiring place where you can truly feel the passion for cycling.
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Constructed in 1917 this dam forms Alpine Lake, which sites between Kent and Bon Tempe Lakes. The road across the top of the dam make it a great place to ride on a loop around the lake.
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This lake was formed by the building of Alpine Dam in 1917. It sits between Kent Lake and Bon Tempe Lake, and is popular for a variety of outdoor activities.
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At the junction of Chicken Shack Fire Road and Ponti Ridge Trail. There are benches, a great view, and trail markers.
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The park pays homage to a 19th-century fishing village of Chinese immigrants who harvested shrimp from the bay. Much of the village has been preserved, and for a couple bucks you can pay to enter and explore the old town and pier.
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At this point on Sky Oaks Road, there is a junction with Shaver Grade Road, which connects with a dense network of trails and dirt roads near Bald Hill in the Mount Tamalpais State Park. From here, you can continue on the paved Sky Oaks Road or go arond the gate on to the gravel Shaver Grade Road.
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Steep heading West can have traffic on SFD
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There are 16 gravel bike trails around San Geronimo, offering a diverse range of experiences. These routes are highly rated by the komoot community, with an average score of 4.5 stars.
The terrain around San Geronimo is quite varied, featuring rolling hills, lush forests, and meandering creeks. You'll encounter a mix of dirt roads, gravel paths, and fire roads, with some routes offering challenging climbs and others providing more mellow biking through meadows and woodlands.
Yes, San Geronimo offers several challenging gravel bike routes. For instance, the Alpine Dam – Alpine Lake loop from Sleepy Hollow is a difficult 40.5-mile trail with significant elevation gain, taking over 5 hours to complete.
For easier rides, the San Geronimo Commons, a 157-acre public open space, offers scenic trails suitable for 'mellow biking' through meadows and diverse ecosystems. While specific easy routes are fewer, you can find moderate options like the Phoenix Lake – Fish Gulch trail junction loop from Fairfax, which is 16.9 miles with a mix of surfaces and scenic views.
San Geronimo's trails wind through diverse ecosystems, including coastal grasslands, oak woodlands, and redwood forests. You can explore ancient redwood remnants in Roy's Redwoods Open Space Preserve or ride along the Cross Marin Trail, which follows an old railbed through redwood forests. Notable landmarks include Natalie Coffin Greene Park 🌳 Ross and the scenic Cross Marin Trail 🌲.
Yes, the region around San Geronimo features several waterfalls. You might encounter them along trails like the Cataract Trail 🌲, or discover specific falls such as Laurel Dell Falls and Fairfax Falls 🌊.
San Geronimo is generally suitable for gravel biking year-round. The diverse ecosystems offer constantly changing scenery. However, for the most comfortable conditions, spring and fall often provide pleasant temperatures and less chance of extreme weather. Winter conditions can bring rain, making some trails muddy, while summer can be warm.
Yes, many of the gravel bike routes in San Geronimo are loops. For example, the Fish Gulch trail junction – Hoo-Koo-E-Koo Fire Road Trail loop from Fairfax is a 24.6-mile route that takes you through forested areas and fire roads, typically completed in about 4 hours 28 minutes.
Many trailheads and open spaces in Marin County, including those around San Geronimo, offer parking facilities. Specific parking information is usually available on individual route pages on komoot. The San Geronimo Commons also provides accessible parking for its trails.
Yes, you can find options for refreshments. Fairfax, a nearby town, is a popular starting point for many rides and offers cafes and pubs. For example, Splitrock Tap & Wheel is a highlight in the area that caters to cyclists.
The area is highly rated by the komoot community, with an average score of 4.5 stars from 4 reviews. Reviewers often praise the diverse landscapes, the extensive network of dirt and gravel roads, and the blend of challenging climbs and scenic views that make for a rewarding gravel biking experience.
Generally, permits are not required for most public trails in the San Geronimo Valley and surrounding Marin County open spaces. However, it's always a good practice to check specific regulations for any particular park or preserve you plan to visit, as rules can vary.
Absolutely. San Geronimo serves as an excellent gateway to other significant outdoor areas. It connects to extensive trail networks within the Marin Municipal Water District watershed and adjoins Mount Tamalpais State Park and Muir Woods National Monument, offering nearly 40 miles of continuous publicly accessible open space. Samuel P. Taylor State Park is also nearby, providing further trail options.


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