Trail Running calendar near Fairfield 2026-2027

Trail running at Tilden Regional Park in Berkeley with 50K, 35K, half marathon, and 10K options; aid stations appear every 5 to 7 miles and the event is cupless so participants carry their own bottle or reusable cup.

Trail races at Stevens Creek Reservoir in Cupertino on September 12, 2026 include a half marathon, an 11K, and a charity 2.5 mile Lollipop Loop. Courses use shaded single track and ridge views with aid stations and a post race BBQ.

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.

A looped endurance event in Auburn, California from September 18–21, 2026 offering timed runs from 6 to 72 hours, a 100 mile race, glow run, and relay options on a one mile loop with full aid support.

Trail runs at Granite Beach on Folsom Lake with new 10 mile and 5K courses, aid stations, age group awards, a finisher beer glass and a postrace meal.

Trail running event in Las Trampas Wilderness on September 19, 2026, offering a half marathon, 10K and 5K with hilly trail terrain and scenic vistas. Remote participation options and a parks campership fundraiser are included.

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.

An ultramarathon and hike at Skyline Wilderness Park featuring a 3.3 mile loop with 550 plus feet of climbing and flexible 1 to 10 loop options. On-site awards, a raffle and a silent wine auction support 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.

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 in Mountain View on September 27, 2026 features 10K and 5K races, a 3 mile walk, and a kids 1 mile fun run, with awards, finish line timing for 5K and 10K, and proceeds supporting the Friends of Stevens Creek Trail.

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.

A trail running event in Cool, California on October 17, 2026 offering 5k, 10k and a half marathon. Proceeds benefit Black Oak Mines Unified School District youth programs and help fund a scholarship to Camp Taylor.