Dirt Fondo 2025 Mt. Tam Epic

Saturday, July 19, 2025

MCBC Dirt Fondo 2024

MCBC DIRT FONDO – Departs from The Marin Headlands, Saturday, July 19!

The 13th annual MCBC Dirt Fondo returns for another year of outdoor off-road adventure! Mark your calendar for Saturday, July 19, 2025, as 300 lucky riders will embark on a 45-mile journey from the Golden Gate to Mt. Tam and back. There is amazing scenery along the whole route and a good mix of trails, fire roads, and tarmac! Friendly faces will greet you at 4 rest stops on the way out as well as on the return and world-class support on course, including marshals, mechanics, and SAG.

The day culminates with a post-ride party among the horses at the Presidio Riding Club Stables in the Marin headlands.

When: Saturday, July 19, 2025 (soft start between 6:30 a.m. and 8:00 a.m.)

Where: Rodeo Valley Trailhead at the Presidio Riding Club Stables in the Marin Headlands

While the Dirt Fondo started as a mountain bike event, run what ya brung (aka Gravel, Cyclocross, or Single Speed)!

The classic route takes riders from the Marin Headlands to the top of Mt. Tam and back on a crisscrossing selection of trails and fire roads.

45, 32, and 24 mile options // Post-ride meal // Well-stocked energizer stations // Dirt Fondo Schwag //  Course Marshals & Sweeps // SAG & radio support // Much more…

The ride begins at the Presidio Riding Club stables at 901 Bunker Road in the Marin Headlands with a soft rollout between 6:00 a.m. and 8:00 a.m. on Saturday, July 19, 2025. There is ample parking across the street, but please carpool if possible.

Register opens in April 2025

Dirt Fondo FAQs

What are the routes?

45 Mile Route – https://www.strava.com/routes/2984701028511893140

32 Mile Route – https://www.strava.com/routes/2984700821142326932

24 Mile Route – https://www.strava.com/routes/2984700611796093588

Can I do these routes on a gravel bike?

All Dirt Fondo routes are planned with mountain and gravel bikes in mind. Upright bars and suspension will have advantages on the trails and rutted fire road segments, but a gravel bike is great for the smoother fire road bits and road segments. Either way, be prepared for some challenges along the way and walk tough sections if it looks too difficult – no one will judge you!

Are e-bikes allowed?

The 32 and 24 mile options are e-bike legal. The 45 mile route includes the Mt. Tam Watershed, which currently considers the e-bikes motor devices, which are prohibited. They will likely be allowed under a pilot program in the future, date tbd. See our stance on e-bikes, and where you can ride them, at https://marinbike.org/resources/e-bike/

Traditional Territory of the Coast Miwok

As you enjoy the trails in Marin, please remember that you are riding within the traditional territory of the Coast Miwok, many of whom are now citizens of the Federated Indians of Graton Rancheria. Please help us acknowledge the Tribe and their continuing legacy as caretakers of their ancestral territory. Do your part to not disrupt the landscape by staying on the trail.

Dirt Fondo 2024 Sponsors


Refunds are not offered for this event; however, transfers of registration to another rider are offered at no extra fee, as late as 5 days before the in-person event. In the case that you cannot attend and you would like to transfer your registration to a friend, please email sandy @ marinbike.org. In the event that the ride has to be rescheduled, we will automatically transfer your registration to the new date; if we are forced to cancel, your fees will go to support the work that MCBC is doing to expand and enhance bicycling in Marin County.


$160 – $260

2025 Dirt Fondo

July 19
Presidio Riding Club, Bunker Road
Sausalito, CA 94965 United States
2024 Dirt Fondo Logo blue

The 13 Year Anniversary of MCBC's Dirt Fondo returns for a day of off-road adventure on Saturday July 19, 2025. 300 lucky riders […]

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