Trail Running calendar near Fairfax 2026-2027

We have found 101 Trailruns within 80 miles of Fairfax. See below where and when you can find the races.

A scenic loop race on Angel Island offering a Half Marathon (two loops) and a 10K (one loop) with ocean and city views, limited to 400 runners. A chartered ferry from Tiburon is required and ferry fees are included in race pricing.

A steep 4.75 mile up and down run, hike, or walk on San Anselmo's Bald Hill that finishes downtown with live music and a t shirt. The third annual event benefits local nonprofits and includes town endorsement.

A PA/USATF cross country race of 3.4 miles at Spring Lake Regional Park in Santa Rosa on August 30, 2026. The 33rd annual Empire Open features rugged dirt trails, three races including a masters division, and a $1,500 prize purse for USATF..

September 2026

Experience the natural scenery of Mount Diablo State Park through a variety of trail races. Runners can select distances ranging from 4 miles to a 50K with spectacular views of the San Francisco Bay Area.

A 6.45 miles trail race in Annadel State Park organized by the Empire Runners Club, held in early September with staggered age and gender starts, limited to 100 runners and awards for the top 13 finishers.

Experience the trails of China Camp State Park with a selection of distances including a 5K 10K and Half Marathon. Participants enjoy a post race festival with beer steins custom medals and local snacks.

A trail running event in Tilden Regional Park near Berkeley offering 50K, 35K, half marathon and 10K courses with stocked aid stations, a cupless policy, and a 350-runner field.

Trail trail races at Stevens Creek Reservoir in Cupertino on September 12, 2026 include a Half Marathon, 11K and a 2.5 mile Lollipop Loop. The USATF sanctioned event is hand timed, capped for the longer distances, and supports wildfire reli..

A trail running event at Calero County Park offering distances from a kids run to a 50K across single-track and dirt roads, with named aid stations, drop bag support, bib color assignments, and time limits for longer races.

Rocky Ridge in San Ramon, CA on September 19, 2026 features a trail half marathon plus 10K, 5K and virtual options. The courses include hills and scenic viewpoints.

The Healdsburg Fitch Mountain Footrace is a long running community event in Sonoma Wine Country that raises funds for Corazón Healdsburg and a kids running team. It features 3K and 10K courses beginning and ending near the Historic Downtown..

A set of trail races at Lake Chabot in Castro Valley offering a Bay Ridge 100k, Firetrails 50 and Golden Hills Marathon with published course and aid station plans, set time limits, UTMB indexing, and finisher awards.

A community ultramarathon and hike at Skyline Wilderness Park in Napa, CA, featuring a 3.3-mile loop repeated up to ten times in an hourly format to raise funds for the Pheo Para Alliance.

Trail running in shaded redwood forest at Sanborn County Park on September 27 2026, with 10K, half marathon and 50K options; steep singletrack, shuttle parking, chip timing and specific mandatory gear for the 50K.

October 2026

Experience a weekend of multisport racing at McNear’s Beach Park featuring an Olympic triathlon, a trail half marathon, and a combined challenge for participants seeking dual events in San Rafael.

Experience a trail half marathon on San Bruno Mountain featuring 2,400 feet of elevation gain and stunning views. Enjoy a scenic route with 93 percent trail coverage followed by a post race meal and finishers medal.

Run by the Sea at Wilder Ranch State Park on October 4, 2026 offers a Half Marathon, 12K and 4K run/walk along mostly flat packed dirt trails with coastal bluff and Monterey Bay views. Organized by the Santa Cruz Track Club; proceeds benefi..

Test your endurance at Lake Merced in San Francisco with a scenic 4.5 mile loop course. Choose between a standard run or tackle ultra marathon distances including the 50K and 50 mile events.

A trail race at Almaden Quicksilver County Park with distances from 5K to 50K. Courses are out-and-back, marked with colored ribbons, include aid stations and toilets, and the longer races reach Bald Mountain and Mt. Umunhum.

A 12.4 mile loop up to the Mount Diablo summit and back with about 4,000 feet of climbing and descending. The race starts and finishes at Mitchell Canyon and includes shuttle service, a post race raffle and a finisher item.

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