Trail Running calendar near Fairfield 2026-2027

A trail event at Acorn Creek Trailhead near Pilot Hill, CA featuring a 10K single lap and a two-lap half marathon across singletrack, creek crossings, and overlooks. The race is limited to 175 runners and benefits the American River Conserv..

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.

Celebrate Halloween with a trail race through San Jose Hellyer County Park. Choose from distances including 5K 10K Half Marathon and Marathon with costume prizes and certified courses.

Trail races in Almaden Quicksilver Park from 5K to 50K over hilly dirt roads and single-track, with two staffed aid stations, drop-bag service for longer distances, and a finisher medal for all participants.

Support student programs and the Oakland Tech Cross Country team at Joaquin Miller Park. Choose between a five kilometer trail race or a one mile fun run through the redwood trees.

Event Details The Rio Del Lago 100 Mile Endurance Run is a trail race held on Saturday, November 7, 2026, starting at Beal's Point in Folsom Lake State Recreation Area, within the Sierra Foothills of California. Course Information The 100-m..

Trail races at Huddart Park with multiple distances, a 6 Hour loop option, cupless aid stations, volunteer credits, customizable swag choices, and a post-race pancake breakfast.

Experience a scenic trail run around the Lake Chabot reservoir and hills. With distances from a 50 yard kids dash to a 50K ultramarathon there is an option for everyone at this Castro Valley event.

Trail races run from Stinson Beach to Mt. Tam on November 7, 2026, with distances from 10K to a 50K that has an 8.5 hour time limit. Awards, finisher medals, aid stations, and post-race food are provided.

A flat trail event at Quarry Lakes Regional Recreation Area offering 5K, 10K, half marathon and youth races, cupless aid stations every 2–5 miles, and a USATF-certified half marathon course.

Trail event in El Dorado Hills with distances from 5K to trail marathon on mostly single-track dirt, rolling hills, a creek crossing, marked aid stations, and enforced time limits; finishers receive a medal.

Trail race at Darrington Trail Head by Folsom Lake offering 5K, 10K, 18M and 36M on rocky single-track with rolling hills, aid stations, drop bags, and a 10-hour overall time limit.

Celebrate Thanksgiving at Hellyer County Park with a trail race along Coyote Creek. Choose from a USATF certified half marathon, 10K, or 5K while competing for a chance to win a turkey.

A Thanksgiving Day trail event at Beals Point offering 5k and 10k courses plus a free 1k kids run for under-6s. The race supports Folsom's Hope, features one aid station, and requires runners to bring a cup or bottle.

A 28.4 mile trail race in Mill Valley with about 9,000 feet of climbing on the Dipsea Trail. The course is an out and back to Stinson Beach that is then repeated to complete the Quad.

Quarry Turkey in Fremont on November 28, 2026 offers a mostly flat half marathon plus 10K, 5K and a short Little Turkeys run for children. The event includes a food drive for Alameda County Food Bank and a virtual entry option.

A seasonal cross country event in San Francisco on 12/6/2026 with live and virtual options. Distances include a 5K, 10K, and a nine mile course; all entrants receive race swag and there is a pre race bib and shirt pickup with Brewfest.

A multi-distance trail event at Calero County Park in San Jose featuring single-track, hills and varied terrain. Aid stations, drop-bag service for the 50K, free parking and support access at Rancho Cañada del Oro are provided.

Peacock Gap Trail Run at China Camp State Park on December 5, 2026 offers 10K, half and 30K trail courses with marked single track and fire roads, chip timing, aid stations, and a cupless water policy.