Trail Running calendar near Fairfield 2026-2027

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.

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 up to the Mount Diablo summit and back with about 4,000 feet of climbing and descending. The race starts and finishes at Mitchell Canyon and includes shuttle service, a post race raffle and a finisher item.

Trail distances from 5K to 35K around San Pablo Reservoir on EBMUD trails, with marked single-track, cupless aid stations, chip timing, and a 300 runner capacity.

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 featuring 100 mile, 50 mile, marathon and 4-person relays, with extensive singletrack, lake views, on-site camping, designated aid stations, and crew access at several points.

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.

Trail races in Walnut Creek on October 17, 2026 offer 30K, Half Marathon, 10K and 5K on dirt trails through Castle Rock Park into Mount Diablo State Park. Courses are marked and GPX files plus staffed aid stations are provided.

A 5k cross country race run in two loops around Willow Hill Reservoir next to Folsom High School, part of the Pacific Association USATF Cross Country Grand Prix, with a $75 bonus for breaking an age group record.

The Quicksilver Trail Challenge on October 17, 2026 in San Jose, CA features trail Half Marathon and 10K races plus a free one mile kids race through Almaden Quicksilver County Park with valley and mountain views.

A themed charity run and community festival on October 18, 2026 in Downtown Roseville, CA, supporting the bleeding disorders community. The day includes a timed 5K, a one mile walk, festival food, carnival games, and a remembrance ceremony.

An endurance event at Beals Point, Granite Bay featuring hourly 4.16 mile laps until one runner remains, plus a 12 hour Mini Last Person Standing option. Aid is available at the start area and runners may set personal aid stations.

A backyard ultra at Beals Point in Granite Bay where runners run a 4.16 mile loop each hour until one remains. A 12 hour Mini format offers the same hourly lap with a fixed limit.

Trail races at Acorn Creek Trailhead near Pilot Hill CA feature a half marathon and a 10K on singletrack with climbs, creek crossings, and lake overlooks. The event is limited to 175 runners and benefits trail maintenance.

A trail race in Bothe-Napa Valley State Park on October 24, 2026 offering Marathon, Half Marathon, 10K and 5K. The single-track course features hills, stream crossings and narrow sections, and the field is limited to 300 runners.

Oakland Hills Trail Run features 10K, half marathon and 35K courses through Redwood Regional Park with technical trails, marked routes, aid stations and chip timing. The event is cupless and limited to 330 runners.