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Fairfax-Bo Ridge Gravel Grinder

 6 votes


43.3 Miles 69.6 Kilometers




3,638' 1,109 m


-3,638' -1,109 m



Avg Grade (2°)


Max Grade (16°)

1,664' 507 m


70' 21 m



All Clear 51 days ago
Some Mud History

Getting forecast...

Maximum dirt, minimum traffic, amazing views along this big, mostly fire road, loop.

S. Lengyel


Gravel grinders on MTB Project? Sure!

This is a 40+ mile mostly dirt loop from Fairfax. It is the type of loop we would want to ride if we were visiting Fairfax on a bike trip. Maximum dirt, minimum traffic, epic views, tough climbs, shady forests, etc. This ride has it all.

This ride is mostly fire road and ranch road doubletrack, linked together by lightly traveled pavement sections. It flows best as a clockwise loop, but can be ridden in either direction. Clockwise does most climbing on pavement, most descending on dirt.

You can do this ride on any knobby tire bike (and I have done it on my full suspension bike), but it is best suited to modern gravel/adventure bikes. At 40+ miles, it would be a long day on a big travel bike, but totally doable. Recommended bikes for this would be gravel bike with 35mm-40mm tires (your most fun), cyclocross bike, or hardtail mountain bike. You can have an epic day on a full suspension bike, of course, it's just going to be slower on the road sections.

This ride is designed for those wanting maximum views AND good mileage.

This ride is not very technically challenging but does have lots of short steep climbs, rutted rooty descents, and lots of miles. Technical rating is moderate. The ride is tough because of distance.
Features: -none-

Need to Know

As always, be prepared with plenty of food, water, tube, pump, multi-tool. There is a 20+ mile section with no services on this ride.

There is water at the Meadow Club, in Samuel P. Taylor campground, and stores in Lagunitas and Woodacre.

Keep cattle gates closed on Bolinas Ridge! Expect cows and dodging cow pies on the lower half of Bolinas Ridge.


This ride starts in Fairfax and climbs through the Marin Municipal Water District watershed around the Meadow Club golf course. You'll climb on the pavement of Fairfax-Bolinas road for approximately one mile before hitting the dirt again on Pine Mountain Fire Road.

Grunt through a steep, exposed, rocky climb before turning onto Oat Hill Fire Road/ Old Vee Road for a rolling (mostly descending) ride to Kent Pump Road.

Enjoy the shade of Kent Pump Road as you make your way to Alpine Dam for a shady 2.4-mile pavement climb to Bolinas Ridge. Bolinas Ridge is an 11-mile section of rolling dirt with shady forests and open grass on old ranch doubletrack. Bolinas Ridge features gorgeous views, shady redwood groves, ferns, flowers, wide open grasslands, cows, and some short steep climbs.

You'll hit the pavement again on Sir Francis Drake Blvd for a 1/2 mile before turning onto the Cross Marin bike path where you'll have no vehicle traffic until you cross back over the creek at Shafter Grade Trail (Kent Dam to Bolinas Ridge).

It's a road burn on lightly traveled back roads through San Geronimo Valley to the last dirt section on Old Railroad Grade Trail back to the neighborhoods in Fairfax.

I placed the start of this ride at Sunshine Bikes in Fairfax because there is a bike shop, brewery, coffee shop and health food store within a 1/2 block. You can start this ride anywhere in Fairfax since parking in downtown Fairfax gets crowded on weekends. There are also numerous options to extend this ride into a true long-distance gravel grinder epic.

Please let me know in the comments what you think of the route!

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Apr 14, 2018
Mark Macdonald
Mar 31, 2018
Fred Flores
I road this on a full suspension mountain bike. Not sure I would do it on a gravel or cross bike. 45mi — 4h 30m
Feb 24, 2018
Alberto Alas
little cold little hard but very fun 56mi
Dec 5, 2017
Piero Giramonti
Nov 11, 2017
Peter B
Nov 5, 2017
Alex Reimers
Aug 6, 2017
Norbert Barbosa
Jun 4, 2017
Justin Pitts

Trail Ratings

  4.5 from 6 votes


in Marin County


  4.5 from 6 votes
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This is an absolutely beautiful ride but I would not describe this as a gravel grinder. My girlfriend and I did the entire route on our cross bikes equipped with 42mm wide tires and found it to be technically very challenging and wished we had chosen our hard tail mountain bikes. We both come from a road bike background so our limited off road experience may have played a part; however, we have both done the 100 mile Lost and Found gravel race and found that to be far less technically challenging. The biggest issues were the descents leading to Alpine Dam and the unrelenting pounding of the northern section of the Bolinas Ridge trail. The sections where the cross bike excelled were southern end of the Bolinas Ridge Trail through the redwoods (spectacular), the section through Samuel P Taylor Park, and on San Geronimo. I’m looking forward to doing this ride again on the mountain bike. May 31, 2016

Thanks for the great review. I have a few more epic "gravel"/adventure rides to post for both Marin and Tahoe area. Stay tuned for more "way off the beaten path" rides. Maybe see you at Lost and Found this weekend! Sandor and Helene (in the big white Ford DIY campervan). May 31, 2016
A A  
I have to agree that this isn't a gravel grinder, and you wouldn't want to do it on a cross bike. I was comfy on a FS 29er though. Erosion and cow traffic have worn down many of the sections that I can imagine were once smooth. First half of this ride was really nice, the second half - mostly on road/bike path, was not worth including. Anyway, thanks for posting the route! Feb 20, 2018

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