Trail Running calendar near Fairfield 2026-2027

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.

A scenic loop trail race around Angel Island with a single-loop 10K and a half marathon that runs the loop twice; ferry transport is required and included in race pricing, and the field is limited to 400 participants.

Explore the scenic trails of Huddart Park and Bear Gulch at this multi distance trail event. Runners can choose from distances ranging from 8K to 50K through redwood forests and lush ferns.

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.

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.

Trail races in Tilden and Wildcat Canyon near Berkeley with 10K, half marathon, 35K and 50K options, aid stations every 5 to 7 miles, a cupless format, and a 350 runner capacity.

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.

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.

JP's Backyard Ultra/Hike is a final edition event in Napa's Skyline Wilderness Park. Participants run or hike a 3.3-mile loop, choosing their own distance up to 33 miles. This free event is a fundraiser, with a suggested donation supporting..

Trail races run through shaded redwood forest in Sanborn County Park on Sep 27, 2026, with 50K, half marathon and 10K options and spectator access.

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 offers 10K, 5K, a 3-mile walk and a kids 1-mile run on Stevens Creek Trail and Shoreline Park, plus a festival and activities. Proceeds benefit 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, California along the American River Canyon rim with live music and free cider. Distances include a 50K, a half marathon and a 5 mile course with aid stations on the longer routes.

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.