Trail Running calendar near Fairfield 2026-2027

Navigate through historic San Francisco neighborhoods and parks in this unique 5K or 10K challenge. Use a custom map to find checkpoints and solve riddles individually or in teams of up to five people.

The Double Dipsea is a longstanding annual 13.7 mile trail race from Stinson Beach to Mill Valley and back, run on mostly single track with many stairs and handicapped starts that create frequent passing among runners.

Join this unique trail run at Folsom Lake SRA where you can compete alone or with your dog. Features 10K and 5K courses with specialized awards for different dog weight classes and finisher medals for all.

Obstacle race weekend at Mahon Ranch near Elk Grove on Aug 29-30, 2026 with Sprint, Super and Kids races, team entry options, and service member discounts.

Trail races at Huddart Park, King's Mountain and Bear Gulch offer measured distances from a 50 yard kids dash to a 50K, with fees listed per distance and registration opening November 11, 2025.

Island loop races at Angel Island State Park with sweeping bay views; a 10K single loop and a Half Marathon that does two loops, limited to 400 participants and requiring ferry transport.

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..

This trail running event in Auburn, California, offers half marathon and 10K distances. The courses traverse the steep and scenic trails of the Mammoth Bar OHV area, known for its rugged climbs and canyon views.

Multi-distance trail event at Mount Diablo offering races from 4 miles to a 50K plus a free kids dash. Mountainous routes have significant elevation gain, marked courses, staffed aid stations, and a cupless hydration policy.

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 multi-distance trail event in Tilden Regional Park on September 12, 2026 featuring 50K, 35K, half marathon, and 10K courses with regular aid stations, cupless policies, event shirts, and a range of finishers awards.

Trail races at Stevens Creek Reservoir include a Half Marathon, 11K and a 2.5 mile charity Lollipop Loop on shaded singletrack and ridge trails. The field is limited and aid stations provide food and drinks.

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.

Dick Collins Firetrails in Castro Valley features a 100k, a 50-mile race, and a marathon on Lake Chabot park trails. The event is UTMB Index and the 50-mile race counts toward the Pacific USATF Grand Prix.