Trail Running calendar near Clayton 2025-2026

The Reservoir Dogs Trail Run in Orinda, CA, offers 10K, Half Marathon, and 35K distances around the scenic Briones Reservoir on East Bay Municipal Utility District (EBMUD) trails. This event features a mix of rolling fire roads, tree-covered single-track, and expansive views of watershed lands, prov..

The SFRC Women's Headlands Half Marathon is a scenic trail running event held in the Marin Headlands, starting and finishing at Rodeo Beach near Sausalito, California. The race features a challenging 12.6-mile half marathon with 2,494 feet of elevation gain, alongside a 6-mile 10K option. Both cours..

The Mile Madness Endurance Run is a multi-day ultrarunning event held at Sunset Whitney Recreation Area in Rocklin, California. The course is a professionally measured 1.05-mile loop featuring 85% dirt trail and 15% paved path, with about 62 feet of elevation gain per lap. Runners can choose from va..

Granite Head 2025 is a premier trail running event held in Granite Bay, California, featuring two challenging courses: a 6.6-mile short course and an 11.2-mile long course. Both races start and finish at Granite Beach, offering scenic trail running experiences. Participants receive a unique tech shi..

The Ruth Anderson Memorial Endurance Run is a prestigious running event held annually in San Francisco, California, since 1986. This endurance race features multiple distances, including 50 miles, 100 kilometers, and 50 kilometers, attracting runners of various skill levels. The course consists of a..

The Mt. Umunhum Trail Conquest-Fall is a trail running event held at Almaden Quicksilver County Park in San Jose, California. The race offers multiple distances including a 5K, 7 Mile, Half Marathon, 30K, Trail Marathon, and 50K.The longer courses venture into the scenic Sierra Azul Open Space Prese..

Go Wild Marin 4 Hr is an adventurous trail and wilderness scramble held on the Tiburon Peninsula in Corte Madera, California. Participants compete individually or in teams of up to five, navigating a custom map to locate as many as 24 checkpoints scattered across trails and wild areas within a four-..

The Napa Lapa Trail Adventure, hosted by Inside Trail Racing, is a unique time-based trail running event held at Skyline Wilderness Park in Napa, California. Participants run as far as possible within set time frames of 3, 6, or 12 hours on a 4.16-mile loop featuring approximately 815 feet of elevat..

Willow Hills XC is an annual 5K cross country race held at Willow Hill Reservoir Community Park near Folsom High School in Folsom, California. Now in its 15th year, the event features a challenging course consisting of two loops of rolling hills around a water reservoir. It is part of the Pacific As..

The California Fall Classic at Lake Sonoma, held in Healdsburg, CA, offers two challenging ultramarathon distances: 100K and 55K. Set against the stunning backdrop of wine country during harvest season, the courses feature relentless single-track trails with majestic views of Lake Sonoma. The 100K s..

The Diablo Summit Stomp is a trail running event held in Walnut Creek, California, featuring distances of 30K, half marathon, 10K, and 5K. The courses traverse dirt trails starting from Castle Rock Park and extend into Mount Diablo State Park, with the 30K reaching the summit of Mount Diablo. The ev..

The Haunted Hills 10K in Redwood City is a unique nighttime running event featuring a spooky, festive atmosphere. Participants run through wickedly decorated neighborhoods, navigating approximately 36 checkpoints along the 10K course. Runners, in teams of one to five, engage in a fun challenge by an..

The Oakland Hills Trail Run, held at Redwood Regional Park in Oakland, CA, offers challenging trail races in three distances: 10K, half marathon, and 35K ultramarathon. Set in a serene redwood forest with towering 150-foot coast redwoods, the course features technical dirt trails and fire roads with..

The Napa Fall Wine Country Marathon, Half Marathon & 10K is an annual trail running event held at Bothe-Napa Valley State Park in Saint Helena, California. Now in its 33rd year, the race features challenging courses through lush single-track trails with hills, streams, and rocky terrain, offering a..

The ZombieRunner Halloween event is a festive running competition taking place in San Jose, CA, featuring a variety of race distances including a 5K, 10K, Half Marathon, and Marathon, along with youth categories and a free Kid's Run. Participants are encouraged to dress in Halloween costumes for a c..

The Almaden Hills Trail Run - Fall takes place in Almaden Quicksilver Park, located in the scenic Almaden Valley near San Jose, CA. This trail running event offers a variety of distances including 50K, Trail Marathon, 30K, Half Marathon, 10K, 8 Mile, and 5K races. The course features a mix of approx..

The Rio Del Lago 100 Mile Endurance Run is a premier ultramarathon held annually in the scenic Sierra Nevada Foothills of California, about 40 minutes east of Sacramento. Starting at Beal's Point in Folsom Lake State Recreation Area, the challenging 100-mile course features diverse terrain including..

The Oakland Tech 5km Fundraiser Race and 1 Mile Fun Run/Walk is set to take place at Joaquin Miller Park, supporting the Oakland Tech Cross Country and Track Team. This event features a scenic 5K trail run and a 1-mile fun run/walk, designed to cater to both competitive runners and leisurely partici..

The NorCal Backyard Ultra, held at Beals Point in Granite Bay, CA, is a challenging endurance running event featuring a 4.2-mile loop course along scenic singletrack trails and lakefront views. Participants must complete each loop within an hour, starting a new lap on the hour, continuing until only..

The Lake Chabot Trail Run, held in Castro Valley, California, offers a variety of distances including 8K, Half Marathon, 30K, Marathon, 50K, and a free Kid's Run for children six and under. The course begins at Lake Chabot Regional Park Marina and loops around the scenic Lake Chabot reservoir and su..