Trail Running calendar near Fairfield 2026-2027

A trail event around San Pablo and Briones Reservoirs offering 5K, 10K, half marathon and 35K on single track and fire roads. Aid stations, race shirts, and a 300 runner capacity are part of the event.

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.

A trail running event in Cool, California on October 17, 2026 offering 5k, 10k and a half marathon. Proceeds benefit Black Oak Mines Unified School District youth programs and help fund a scholarship to Camp Taylor.

A multi-distance trail event at Lake Sonoma on October 17-18, 2026, offering 100 mile, 50 mile, marathon and relay options. Courses use extensive singletrack with lake views, aid stations, crew access, and free on-site camping for participa..

Trail races in Marshall Gold Discovery State Historic Park offer distances from a Kids Run to a half marathon on singletrack and paved sections, with marked courses, aid stations, a 4.5 hour time limit, and on site parking for a fee.

Trail event in Walnut Creek on October 17, 2026 offering 30K, half marathon, 10K, 5K and a remote runner option. Walkers are welcome and age-group awards are given.

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.

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 in Granite Bay where runners complete an hourly 4.16 mile loop until one remains. A 12 hour Mini Last Person Standing uses the same format with a fixed time limit.

A repeating 4.16-mile trail loop event at Beals Point where runners start a new lap each hour until one remains; a Mini version ends after 12 hours. Aid is only at the start/finish and personal aid areas are encouraged.

Trail races near Pilot Hill, CA featuring a half marathon and a 10K on singletrack with creek crossings and views; the event is a fundraiser for the American River Conservancy and is limited to 175 participants.

Trail marathon, half marathon and 10K in Bothe-Napa Valley State Park on October 24, 2026, limited to 300 runners. Single-track course with hills, streams and rocky sections; orange ribbon markings, one aid station, no headphones allowed.

Trail races in Redwood Regional Park near Oakland on October 24, 2026 include 10K, half marathon and 35K with significant elevation gain. The event uses chip timing, cupless aid stations and has a 330 runner capacity.

A Halloween-themed running event at Hellyer County Park with 5K, 10K, half and full marathon distances, youth divisions, a free kids' dash, a costume contest, certified half and full courses, aid stations every 2-4 miles, and cupless hydrat..

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..

A trail event at Huddart Park on November 7, 2026 featuring multiple distances, a 6 Hour Challenge and a youth dash, with aid stations, chip timing and a post race pancake breakfast.

A trail race at Lake Chabot Regional Park in Castro Valley offering distances from an 8K and half marathon up to 50K plus a free kids 50 yard dash. The course loops the reservoir with marked routes, aid stations every 4 to 5 miles, and cupl..

Trail races from 10K to 50K based at Stinson Beach with steep climbs to Mt. Tam, technical trails, chip timing, cupless aid stations, and age-group and overall awards.