Trail Running calendar near Fairfield 2025-2026

The Mt. Umunhum Marathon, Race to the Top and Down, is a challenging trail running event held in Almaden Quicksilver County Park, San Jose, California. This marathon features a rugged course that begins at the Hacienda Entrance and ascends to the summit of Mt.Umunhum, one of the prominent peaks in t..

The Rocky Ridge Trail Half Marathon is a challenging trail race held in the scenic Las Trampas Wilderness near San Ramon, California. Scheduled for September 20, 2025, the event features a half marathon, 10K, and 5K distances. Known for its tough terrain and significant elevation, the half marathon..

The Dick Collins Firetrails will take place in Castro Valley from Saturday 27 September 2025 to Sunday 28 September 2025. You can run between 42 and 100 kilometers.

The Pacifica Summit Run is a scenic trail running event held at San Pedro Valley State Park in Pacifica, California. It offers two race distances: a 10K and a half marathon. Runners experience challenging switchbacks and enjoy stunning postcard views of the Pacific Ocean coastline from the tallest m..

The Sunset & Cider Trail Races, held in Auburn, California's scenic American River Canyon, offer three trail running distances: 50K, 13.1 miles, and 5 miles. The courses feature mostly runnable single-track trails with moderate elevation gains—3,875 ft for the 50K, 2,082 ft for the half marathon, an..

The Spartan Trail - San Jose Trail Challenge takes place at Sanborn County Park in Saratoga, California, nestled on the eastern slopes of the Santa Cruz Mountains. This scenic event offers challenging trail runs with distances of 10K, 21K (half marathon), and 50K. Participants navigate steep climbs..

The Trailblazer Race in Mountain View, CA, is an annual family-friendly event featuring 10K and 5K runs, plus a 3-mile walk along the scenic Stevens Creek Trail and Shoreline Park. The courses are fast, flat, and stroller-friendly, offering beautiful views of wildlife, salt ponds, and surrounding mo..

The Star City San Bruno Mountain Half Marathon & 5K, held in Brisbane, California, offers a scenic trail running experience with spectacular views of the Pacific Ocean, San Francisco Bay, and the city skyline. The half marathon course is 93% trail, featuring 2,400 feet of elevation gain and a thrill..

The Reservoir Dogs Trail Run in Orinda, CA, offers a scenic trail running experience around the Briones Reservoir on EBMUD trails, typically permit-only. Scheduled for October 4, 2025, the event features three distances: 10K, Half Marathon, and 35K, all starting and finishing at the San Pablo Reserv..

The Auburn Half Marathon, held in Auburn, California—known as the Endurance Capital of the World™—offers trail running on the scenic Western States Trail. The event features a half marathon, 12K, and 5K races, all starting from Auburn Overlook Park and winding through the Auburn State Recreation Are..

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 Tails & Trails Charitable Walk/Run takes place in Windsor, California, at 11010 Estate Lane. This event features two race options: a 5K run and the Dogwood Dash. It is organized to support charitable causes, creating a community-focused and friendly atmosphere.While specific details about the co..

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 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 shirt and e..

The Ruth Anderson Memorial Endurance Run is an ultradistance race held annually in San Francisco, California, at scenic Lake Merced. The course features a mostly flat, USATF-certified 4.48-mile loop on paved paths and groomed dirt shoulders around the lake, with about 100 feet of elevation gain per..

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 a challenging 50K.The longer courses venture into the scenic Sierra Azul Op..

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, using a custom map to locate as many as 24 checkpoints scattered across trails and wild areas within a four-hour..

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. Instead of racing a fixed distance, participants run as far as possible within 3, 6, or 12-hour time limits on a challenging 4.16-mile loop fe..

The John Lawson Tamalpa Challenge is a cross-country running event held annually at China Camp State Park in San Rafael, California. The 2025 edition features three races, each approximately 4.2 miles long, primarily on rolling single-track trails with a short stretch on asphalt. The event honors Jo..

The Lake Sonoma 100K and 55K, also known as the California Fall Classic, is a challenging ultramarathon held at Lake Sonoma, California, set amidst the scenic wine country during harvest season. The event features two distances—100 kilometers and 55 kilometers—on demanding courses that traverse mile..