Trail Running calendar near Fairfield 2026-2027

Rocky Ridge is a trail running event at Las Trampas Wilderness in San Ramon, California on September 19, 2026. It features a half marathon plus 10K and 5K courses with uphill trail sections and scenic vistas.

A community fundraising run in Healdsburg offering 10K and 3K courses that begin and end near the Historic Downtown Plaza. The 10K loops around Fitch Mountain and the Russian River while the 3K is a flat in-town loop for families and walker..

A trail 5K at San Pedro Valley Park on September 20, 2026, with a kids run and member picnic. The course features an uphill switchback first mile, scenic mid-mile views, and a flat fast final mile.

A multi-distance trail event at Lake Chabot Regional Park offering a Bay Ridge 100k, Firetrails 50 mile, and Golden Hills Marathon with UTMB Index status, published time limits, and finisher awards.

A community ultramarathon and hike on a 3.3 mile loop at Skyline Wilderness Park in Napa supporting the Pheo Para Alliance. Participants can do one to ten loops with alternating loop directions each hour and on site aid and awards.

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.

Trail races along the Western States Trail near Auburn, California on September 27, 2026. Distances include a half marathon, 12K and 5K with electronic chip timing and finisher medals and t shirts.

Trailblazer Race on September 27, 2026 in Mountain View features a 10K, 5K, 3 mile walk and a 1 mile kids run. Proceeds support the Friends of Stevens Creek Trail and free kids activities are offered.

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.

Trail races in Auburn, CA along the American River Canyon with 50K, half marathon, and 5-mile options, post-race cider and a commemorative glass, plus age group awards and a charity matching program.

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.

Granite Head Trails & Ales Trail Races feature 6.6-mile and 11.2-mile courses. Runners get a tech T-shirt and can enjoy post-race fajitas and a beer. The event is the final race in a local trail running series.

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 from Mitchell Canyon to the Mount Diablo summit and back, featuring about 4,000 feet of climbing and descending. The entry fee includes shuttle service, a raffle entry, and a finisher item.

A trail event around San Pablo and Briones Reservoirs offering 5K, 10K, half marathon and 35K on single track and fire roads. Aid stations, race shirts, and a 300 runner capacity are part of the event.

Insomnia is a night trail race in the Sierra Nevada foothills offering 35K, 14K and 5K options. Courses are marked with reflective ribbons and headlamps are required; the 35K has a 5 hour 30 minute overall cutoff.

Trail running in Cool, California with 5k, 10k and half marathon options on Sierra Foothills trails. Proceeds support Georgetown Divide Ready by 21 and a Camp Taylor scholarship; family packages, childcare, and a post-race breakfast are inc..

A multi-distance trail event at Lake Sonoma on October 17-18, 2026, offering 100 mile, 50 mile, marathon and relay options. Courses use extensive singletrack with lake views, aid stations, crew access, and free on-site camping for participa..

Run through the historic site of the 1848 gold discovery in California. This event features multiple trail distances from a 5K to a Half Marathon on scenic singletrack paths along the American River.

A trail running event at Mount Diablo in Walnut Creek on October 17, 2026 offering 30K, Half Marathon, 10K and 5K courses on hilly trails where mud and creek crossings are possible.