Trail Running calendar near Thornton 2026-2027

A high Sierra trail race on August 8, 2026 near Horse Canyon Trail Junction, offering four distances up to a 50K run as three 10.5 mile loops with about 7,500 feet of climbing. Two aid stations and a 100 runner limit are in place.

Trail races in Lafayette on August 8 2026 include a half marathon, 10K and 5K through Briones Regional Park. All courses have hills and use electronic chip timing; finishers receive medals and shirts.

The 50th Pinecrest Run on August 9, 2026 features a five-mile route around Pinecrest Lake and a one-mile pavement race, serving as a fundraiser for Pinecrest Expedition Academy; pets are not allowed.

An annual single-loop 50K ultramarathon in Muir Beach, California, traversing famous Marin trails with about 6,500 feet of elevation gain and ocean and Bay Area views.

Experience the trails of Redwood Regional Park in Oakland. Runners can choose from distances ranging from a 50 yard kids dash to a 50K ultramarathon through scenic ridge lines and redwood groves.

Trail races on hilly mixed dirt and single track at Almaden Quicksilver Park with distances from 5K to 50K, aid stations, drop bag service for longer races, and mandatory course markings and cutoffs.

A five kilometer trail run along the Lands End Trail in San Francisco with views of the Golden Gate and the Pacific Ocean. The event lists a $10 entry fee, awards finisher ribbons, and requests no headphones or pets on course.

A community fundraising race in Oakland that supports the Oakland Cubs youth running team and its scholarship programs. The event features a Kids Fun Run and 5K trail runs at 3594 Sanborn Dr on August 16, 2026.

A map-based navigation event in Fillmore and Japantown on August 22, 2026 where individuals or teams of up to five follow a custom map to 20 to 30 checkpoints across 5K and 10K courses, then enjoy refreshments at the finish.

The Double Dipsea is a longstanding annual 13.7 mile trail race from Stinson Beach to Mill Valley and back, run on mostly single track with many stairs and handicapped starts that create frequent passing among runners.

A multi-distance trail event on August 22, 2026 around Jenkinson Lake with a 100-runner daily cap, starts at Scales Parking Lot and most races finish at the Waterfall Trailhead, with aid stations and a $5 day use parking fee.

A trail event at Granite Beach on August 23, 2026 offering 5K and 10K courses for runners and their dogs, with finisher medals and dog bandanas; aid stations provide drinks and gels and dogs have their own water.

Obstacle-course weekend at Mahon Ranch near Elk Grove on Aug 29-30, 2026, featuring Sprint (5 km), Super (10 km), a kids race, spectator access, team entries, and service member discounts.

Trail races at Huddart Park, King's Mountain and Bear Gulch offer measured distances from a 50 yard kids dash to a 50K, with fees listed per distance and registration opening November 11, 2025.

A loop trail race around Angel Island near Tiburon offering a 10K single loop and a half marathon that repeats the loop. The course has panoramic Bay Area views, a 400 runner limit, and a mandatory ferry to the island.

A steep 4.75 mile up and down run, hike, or walk on San Anselmo's Bald Hill that finishes downtown with live music and a t shirt. The third annual event benefits local nonprofits and includes town endorsement.

A PA/USATF cross country race of 3.4 miles at Spring Lake Regional Park in Santa Rosa on August 30, 2026. The 33rd annual Empire Open features rugged dirt trails, three races including a masters division, and a $1,500 prize purse for USATF..

Trail races at Mammoth Bar OHV Area in Auburn State Recreation Area on September 6, 2026. Options include a 13.1 mile half marathon and a 6.2 mile 10K, each with notable elevation gain and staffed aid stations.

Experience the natural scenery of Mount Diablo State Park through a variety of trail races. Runners can select distances ranging from 4 miles to a 50K with spectacular views of the San Francisco Bay Area.

A 6.45 miles trail race in Annadel State Park organized by the Empire Runners Club, held in early September with staggered age and gender starts, limited to 100 runners and awards for the top 13 finishers.