Trail Running calendar near Thornton 2026-2027

We have found 157 Trailruns within 80 miles of Thornton. See below where and when you can find the races.

Experience the final 70 miles of the Western States trail during this three day training event featuring supported runs of 19, 20, and 32 miles through iconic canyon terrain and mountain climbs.

Trail races at China Camp State Park in San Rafael feature single-track routes with bay and Mount Tam views. Courses include a climb starting around 1.5 miles and distances from 3.1 to 13 miles.

A trail event on the El Dorado Trail in Placerville on May 23, 2026, offering distances from a kids run to a half marathon, paved and unpaved sections, aid stations, color-coded course markings, and medals for finishers.

A trail running event at Point Pinole on May 30, 2026, offering a half marathon, 10K and 5K. The original Brazen Racing event welcomes runners and walkers and includes bib pickup, posted results, free photos and volunteer roles.

Experience a technical trail race through the redwood groves of Joaquin Miller and Redwood Regional parks. Choose from multiple distances ranging from an 8K to a 50K ultra marathon on accurately measured courses.

A community 5K and 10K run/walk at Seal Point Park in San Mateo on May 30, 2026, paired with a complimentary Wellness Fair. Race registration includes a t-shirt and finisher medal and team entries are eligible for a prize.

A multi-distance trail event at Calero County Park in San Jose on May 30, 2026, featuring single track, dirt paths and hilly terrain up to 50K, with aid stations, free parking and drop bag support for the 50K.

An evening trail event at Dos Rios State Park near Modesto offering 3 mile and 5 mile runs on fire roads along the Tuolumne River. Free registration and an informal post run gathering with donations supporting park rangers.

Trail races on May 31, 2026 in Arnold, CA offer distances from 5k to a new 50k ultra across the Arnold Rim Trail and White Pines Lake Park, with proceeds supporting the Arnold Rim Trail Association.

Global Running Fest at Sports Basement Berkeley on May 31 features free road, trail, and kids runs, brand shoe demos, live music and raffles with over $5,000 in prizes. Beer sales benefit the youth program Running for a Better Oakland.

June 2026

A free community festival in San Francisco hosted by UltraSignup with social group runs of about 3.2 or 4.5 miles, an expo with brands and race directors, a pancake breakfast, raffle prizes, shoe demos, and local partners.

A 10km trail run on the Olmsted Loop at Auburn State Recreation Area in Cool, California on June 6, 2026. The race takes place the same day as the Coolest Ride and Tie and Equathon events.

The Cool Summer Night Run will take place in Cool on Saturday 6 June 2026. You can run 10 kilometers.

Trail races on the north shore of Lake Natoma in Fair Oaks with 5K and 10K courses through oak bluffs, wetlands, and historic dredge terrain. Proceeds benefit the Rachel Anne Gray Memorial Scholarship.

A trail event at Almaden-Quicksilver County Park on June 7, 2025 offering distances from 5K to 50K, steep climbs, marked courses, aid stations, and toilet facilities. The 52 mile race is not held in 2025 and is planned to return in 2026.

Scenic trail runs on the north shore of Lake Natoma in Fair Oaks with 5K, 10K and a kids run under 10. Hosted by the Fair Oaks Recreation & Park District, proceeds benefit the Rachel Anne Gray Memorial Scholarship.

The Community Hike & Trail Run Series - Richmond will take place in Montalvin Manor on Saturday 6 June 2026.

Experience the 42nd annual Lake Chabot Trail Challenge featuring a scenic half marathon loop and a paved 5K run. Enjoy views of the San Francisco Bay and Mt Diablo while competing for medals on chip timed courses.

A 100-mile point-to-point ultramarathon on June 13, 2026, from UC Berkeley to Skyline High School in Oakland, featuring about 18,000 feet of ascent across East Bay ridgelines, redwood forest, and lake-shore fire trails with a 33-hour limit.

Trail weekend in Cool, California with looped 13.5 and 11.5 mile courses forming distances from 5K to 100K. Marked single track and fire roads, live chip timing, aid stations, and finisher awards for every distance.

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