Trail Running calendar near Fairfield 2026-2027

A charity trail run on March 22, 2026, at Lake Lagunitas near Fairfax, CA. The 10 km course includes technical terrain and ~400 feet of elevation change, with proceeds beyond event costs donated to Evidence Action's Safe Water Now program.

A half marathon on March 22, 2026 in La Honda, California, the Horseshoe Lake course runs through Skyline Ridge Open Space Preserve with ocean and bay views. The trail mix and 2230' ascent support The Hatuey Project with entry fees matched..

A mostly flat event at Quarry Lakes in Fremont on March 28, 2026 offering half marathon, 10K and 5K distances. Routes follow dirt fire trails with gravel sections and a short paved segment along the Alameda Creek Trail.

A trail race on March 28, 2026 at American River Overlook Park offering 5K, 10K, Half and 35K routes on Western States trail sections, with technical single-track, major climbs, cupless aid stations, chip timing, and a 400-runner capacity.

Trail races along single track by Folsom Lake on March 28, 2026, with 5K, 10K, 8 Mile and half marathon options. Courses feature dirt and rock surfaces, rolling hills, marked navigation and aid stations, and a commemorative medal for finish..

Trail races in the Marin Headlands near Mill Valley offering marathon, half marathon and 10K routes on single track and fire roads with views of the Golden Gate Bridge, San Francisco Bay and the Pacific Ocean. The field is limited to 400 pa..

Trail runs on Mount Diablo on April 4, 2026 offering 50K, half marathon, 10K and 5K distances with a portion of fees supporting Save Mount Diablo. The half marathon is included in the Brazen Ultra Half Series.

Trail events on April 4, 2026 from Folsom to Auburn include a 50 mile endurance run plus 25 and 10 mile options, with on-course aid, professional timing, finish medals, goody bags, and post race food and beverages.

Run the scenic, hilly trails encircling Angel Island with views of the Golden Gate Bridge and San Francisco Bay. Choose between a 10K loop or a half marathon that does the loop twice. The event includes ferry transport and is limited to 400..

Springtime trail races at Lake Sonoma on April 11, 2026 feature a Western States qualifying 100K, a 50K that crosses the Lake Sonoma bridge, and a women-only Trail Sisters half marathon with shuttle service.

Multiple marked trail distances circle Lake Chabot reservoir in Castro Valley, from a free 50 yard kids dash to a 50K. Aid stations occur every 4 to 5 miles and the event operates cupless, so bring a personal cup or soft flask.

A women focused 10K in Auburn on April 11, 2026 featuring scenic trail loops, finisher shirts, age group awards and a raffle with four winners earning a trip to a women only running camp in Spain.

Explore the rolling hills of Cronan Ranch at the Magnolia Magic River Trail Run. This event offers a range of distances on dirt and rock trails, from a 5K to a 50K ultra. All participants receive a medal and access to aid stations along the..

Event Overview The Calistoga Mountain Run is a trail running event with distances of 50k, 35k, a half marathon, and a 10k. It starts in downtown Calistoga, California. The routes take runners onto trails and into Robert Louis Stevenson Stat..

The Outlands Endurance Race takes place on scenic trails at Folsom Lake's Peninsula Campground. Choose from 25K, 50K, or 50 mile distances on runnable single and double track. All runners get custom swag and a post race meal.

Trail races in April 2026 at Del Valle Regional Park offering Half Marathon, 10K and 5K distances with electronic chip timing. Finisher medals and t shirts are provided and walkers and hikers are welcome.

Trail race at Skyline Ridge Open Space Preserve on April 18, 2026 offering distances from a kids 50 yard dash to a 50K. Routes run mostly on the Bay Area Ridge Trail with marked aid stations and a cupless hydration policy.

A community fundraiser at Spring Lake Regional Park on April 18, 2026 featuring a half marathon, 10K and 5K. The low-waste event donates a portion of proceeds to Trione-Annadel State Park and includes a medal, shirt and post-race snacks.

A trail running event in San Carlos on April 18, 2026 offering 1K kids, 5K, 10K and a new 15K with substantial climbing through Big Canyon Eaton and Pulgas Ridge. Festival atmosphere at Crestview Park with timed results and awards.

Trail races through Huddart County Park and Purisima Creek Redwoods on April 18, 2026, offering 10K, half, 35K and 50K courses with chip timing and marked aid stations. The event is limited to 450 runners and is a cupless format.