Mountain Biking Trails in Marin — Brought to You by Access4Bikes

Access4Bikes is a non-profit organization 100% dedicated to maintaining and expanding mountain bike trail access in Marin County, California. We steward over 20 miles of trail on public and private lands and are always advocating for more. We also engage our community through our women’s initiative, group rides, and fun events, including the Marinduro, Ales & Trails, Biketoberfest, and members-only appreciation parties. Trails are maintained with the help of incredible volunteers. Check out our calendar for Trail Work Days and join the fun!

Our vision

Marin County is a place where mountain bikers 1) have access to sustainable, professionally built and managed singletrack, 2) can enjoy shared spaces without conflict with other trails users, and 3) can find and thrive in a supportive community.

Our values

Good Stewardship: We promote sustainable, responsible trail use. As good stewards, we work with land management partners to expand and protect Marin singletrack. Inclusivity:  We are a vibrant, inclusive community – our doors and our trails are open to all. We value diversity and believe that everyone has the right to access rad trails on two (or more) wheels. Fun: We work hard and we play hard. Mountain biking is also the most fun as a group activity, that’s why we put on awesome events that bring us all together.

Pillars of our work

Advocacy – More singletrack. We are the voice for mountain bikers in Marin. We work to affect change in both political and private arenas with the aim of ensuring equitable and environmentally sustainable land-use practices. 

Stewardship – Better singletrack. We are expert trail builders who are passionate about bringing the best singletrack experiences to our community.

Community – More fun for all. We like to party. Whether it’s group rides, races, festivals or skill clinics, we work to grow and support a thriving, diverse community of happy shredders.

Measuring impact

Our work is about ensuring that everyone can have the maximum amount of fun possible on a mountain bike across Marin County. Here's how we measure success each year:

• Miles of singletrack in planning and development: 5

• Miles of singletrack under A4B stewardship: 20

• Thriving volunteer program: 200+ contributing 2,000+ hours annually

• Engaged following: 3,000+ community members engaged in advocacy, trail building, and events

• Ongoing participation in public and 1-1 meetings with land-use decision makers to advocate for more and better single track

Mountain biking in Marin is a magical experience, but we need your support!

It’s no secret Marin is a special place. Multitudes of people — from Marin as well as internationally — find “it” out on the trails of Marin. The redwoods and majestic oaks, the coastal vistas, the San Francisco and Bay views. The serenity, the challenge, the immersive experience, the community. These are just some of the things that draw us in and keep us coming back for more.

We believe bikes are an appropriate way to experience all the above on much of our public lands. We also believe sharing the trails with other user groups is not just feasible, but productive.

We can’t make it without your support. Whether through volunteering or donations, we need and rely on the mountain bike community to help our organization accomplish our mission of maintaining and expanding mountain bike trail access in Marin. Donate today!

Grants & Scholarships

A4B is dedicated to improving the Marin mountain bike experience both now and for the future.

SCHOLARHIPS: We take seriously our role in stewardship and part of that is fostering future generations of engaged mountain bikers. We began a scholarship program to cover the cost for two NorCal High school Cycling League student-athletes to attend a week long Trail Stewardship Camp.

GRANTS: Continuing with our commitment to the future of mountain biking in Marin (and beyond) we are proud to announce our A4B Youth Team/Club Grant program. Up to $2000 is available to mountain bike teams and clubs that complete the requirements!