Trail Running calendar near Fairfield 2026-2027

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..

Trail races at Mammoth Bar OHV Area in Auburn State Recreation Area on September 6, 2026. Options include a 13.1 mile half marathon and a 6.2 mile 10K, each with notable elevation gain and staffed aid stations.

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 September 12, 2026 trail event in Berkeley featuring 10K, half, 35K and 50K courses through Tilden and Wildcat Canyon with chip timing, regular aid stations and a cupless aid policy.

A trail race at Stevens Creek County Park in Cupertino offering a Half Marathon, 11K, and a charity 2.5-mile Lollipop Loop with aid stations and post-race barbecue.

Run through Bishop Ranch and San Ramon in this diverse racing event. Choose between a half marathon, 10k, 5k, or beer mile before enjoying unlimited tastings with your finisher medal.

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.

The Golden Gate Park XC Open will take place in San Francisco on Sunday 13 September 2026. You can run 4 miles.

Mile Madness is a looped trail endurance event in Auburn, California, held September 18-21, 2026. Timed events run from 3 to 72 hours with a 0.75 mile loop and options including a 100 mile race plus on-site aid and amenities.

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 offering Half Marathon, 10K and 5K; the half marathon is noted as non-flat and features trails and views.

Dick Collins Firetrails in Castro Valley on September 26, 2026 features a Bay Ridge 100k, a Firetrails 50 mile and the Golden Hills Marathon with UTMB Index status and organizer specified time limits.

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.

Trail race in Auburn on September 27, 2026 featuring a half marathon plus 12K and 5K with much of the half on the Western States Trail.

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.

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.