Trail Running calendar near Fairfax 2026-2027

A family-friendly Thanksgiving weekend event at Quarry Lakes Regional Park offering a fast, mostly-flat half marathon, 10K, 5K and a free kids' sprint. The race supports the Alameda County Community Food Bank.

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.

An urban single-loop ultra from Twin Peaks in San Francisco offering 50K and 50 mile options, informal aid from volunteers, a mile 25 cutoff for the 50 mile, and support for the Shoes For Runners charity.

Trail races through redwood groves at Sanborn Regional Park with a half marathon, 10K and 5K. Routes use single track trails and chip timing, and walkers and hikers are welcome.

Forest and ridge single-track runs in Woodside, California with 10K, half, 35K and 50K options, chip timing, aid stations, and cupless hydration requirements.

Trail races at Lake Chabot in Castro Valley on December 31, 2026 include a half marathon, a 10K and a 5K. Hikers and walkers are welcome and runners can repeat the course on January 1 to earn the mega medal or combine both halves for a full..

A New Year's Day running event at Lake Chabot in Castro Valley offering 5K, 10K and a half marathon. The half marathon is part of the Brazen Ultra Half Series and the event includes bib pickup, free photos, results and volunteer options.

A winter trail event at Almaden Quicksilver County Park offering distances from a kids run to a 50K, marked dirt-road courses, aid stations with toilets, drop-bag service for longer races, and measurable elevation gain.

A trail race in Huddart Park near Woodside CA on January 17, 2027 offering distances from an 8K to a 50K plus a free kids 50 yard dash. Courses run through redwoods, are well marked, and feature stocked aid stations.

Run through the towering redwoods and lush ferns of Huddart Park in Woodside. This trail event offers multiple distances from a five mile race to a 50K ultramarathon plus a free dash for children.

Experience the magic of the Golden Gate Bridge and the Marin Headlands. This Spartan Trail event offers distances from 15k to 50 miles with panoramic mountain and sea views.

Experience scenic bay views and varied terrain at Coyote Hills Regional Park with half marathon, 10K, and 5K distances. Enjoy a mix of dirt trails and boardwalks on courses designed with minimal climbing.

Experience the coastal beauty of the Marin Headlands at the Golden Gate Trail Run. Choose from distances ranging from a 50K trail race to a fun kids dash with views of the Golden Gate Bridge and San Francisco.

Mt. Umunhum Trail Conquest (Winter) is a multi-distance trail event at Almaden Quicksilver County Park offering races from a kids run to a 50K with marked out-and-back courses, multiple aid stations, and summit sections to Bald Mountain or..

Jed Smith Ultra Classic on February 6, 2027 is a USATF certified loop event on the American River Parkway offering 50 mile, 50 k, marathon, 30 k and half marathon distances with two aid stations and race day packet pick up.

Run or walk along the San Francisco Bay starting from the San Leandro Marina. Choose from half marathon, 10K, or 5K distances with professional timing and custom finisher medals for all participants.

Experience the unique Coastal Mountain Habitat and Pacific Coast views at this trail event in Pacifica. With distances from a kids dash to a 50K there are options for many different types of trail runners.

Trail races in Sanborn County Park on mostly single track, technical forest trails with multiple distances, significant elevation gain, marked courses, and full aid at key points.