Trail Running calendar near Fairfield 2026-2027

We have found 110 Trailruns within 80 miles of Fairfield. See below where and when you can find the races.

A scenic 10km loop trail run in Cool, California. The course features rolling hills, canyon views, and a fully stocked aid station midway.

The Coolest 10km Trail Run is set for June 6, 2026 in Cool, CA. Participants will run a 10km course on the scenic Olmsted Loop Trail.

A trail event in Castro Valley on June 7, 2026 offering a chip timed half marathon and 5K with on-course water, first aid support, guaranteed t-shirts for early registrants, and age division awards.

The Bay Area 100 is a point-to-point 100-mile ultramarathon journey through the East Bay hills, starting at UC Berkeley. With 18,000ft of climbing and a 33-hour limit, it traverses diverse terrain from redwood forests to exposed ridges. It..

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The Cool Moon Trail Races offer six distances from 5K to 100K on scenic, well-marked loops near Cool, California. The event spans two days, with live tracking and multiple aid stations on course. All finishers receive a medal and shirt, wit..

A 100-mile trail race in Cool, California using repeated 13.5- and 11.5-mile loops, with single track and fire roads, aid stations, live tracking, a 37-hour finish cutoff, and pacers allowed after mile 38.5.

The Pena Passage offers trail races through the scenic Lagoon Valley Park. Choose from a challenging 30K with technical trails or shorter 5K and 10K routes. The event includes aid stations and a partnership supporting mental health awarenes..

Live and virtual 5K, 10K and half marathon at Lake Chabot Regional Park in Castro Valley, June 26 to 29, 2026. Courses mix paved and trail sections with aid stations; live participants receive a shirt, handcrafted woodallion and beer sample..

July 2026

The 14th Bay 2 Bankers offers a unique team adventure through San Francisco. Navigate a 5K or 10K course from Ghirardelli Square using a custom map. Teams of up to five can enjoy post-run refreshments.

Trail races on Mt. Tam near Stinson Beach offering 10K, half marathon, and 30K courses with steep climbs, technical single-track, cupless aid stations, chip timing, and a 300-runner capacity.

Trail races in Auburn, CA on July 26, 2026 with long and short courses across single-track mountainous trails, canal sections and dirt roads. Post-race items include a tech shirt, finisher medal, beer for age 21 or older and food.

August 2026

Trail races at Rodeo Beach in the Marin Headlands offering 8K, half marathon, 30K and 50K on coastal singletrack and fire roads; chip timed, cupless, capacity 350.

One of America's oldest 50k races, the Skyline Endurance Run is a scenic August loop starting at Lake Chabot Marina. Known for strong community support and aid stations, it finishes with a plant-based BBQ. The event also features a half mar..

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Bear Creek 2026 offers a hilly half marathon, 10K, and 5K on August 8 in Lafayette, CA. The scenic trail course features beautiful views and a rewarding downhill finish. All finishers get a custom medal and shirt, and walkers are welcome.

A single loop 50K ultramarathon in Muir Beach, California on Saturday, August 15, 2026. The course uses notable Marin trails, includes about 6500 feet of elevation gain, and features coastal and Bay Area views.

An orienteering style 5K and 10K in San Francisco where solo runners or teams of up to five use a custom map to visit up to 30 checkpoints, answer simple multiple choice questions, and enjoy refreshments at the finish.

Tackle the legendary Double Dipsea, a 13.7-mile out-and-back on the historic Dipsea Trail from Stinson Beach. This unique race features a handicapped start, putting all runners on a single-track course of constant passing. Experience the hi..

Trail run in Huddart Park near Woodside, California on August 30, 2026 offering distances from 8K to 50K plus a free kids 50 yard dash. Courses run on single track and dirt roads with aid stations every 5 to 9 miles.

September 2026

This trail running event in Auburn, California, offers half marathon and 10K distances. The courses traverse the steep and scenic trails of the Mammoth Bar OHV area, known for its rugged climbs and canyon views.

Diablo Trail Run on September 6, 2026 in Clayton CA offers distances from a 4 mile Mitchell Canyon course to a 50K, plus a free kids 50 yard dash for age six and younger. Courses use dirt roads and single track with aid stations every 3 to..