JP's Backyard Ultra

Berkeley Trail Adventure is an Inside Trail Racing event set in Berkeley, CA, spanning Tilden Regional Park and Wildcat Canyon. Distances offered are 50K (31 miles), 35K (21.6 miles), half marathon (13 miles), and 10K. The course blends technical dirt trails and non-technical fire roads, with about..

Reservoir Dogs Trail Run, held in Orinda, CA on October 4, 2025, features three distances—10K, Half Marathon, and 35K—starting and finishing at the San Pablo Reservoir Recreation Area in EBMUD land. This race was the first to completely circumnavigate Briones Reservoir on permit trails, offering tre..

Go Wild Marin offers a trail and wilderness navigation challenge in Corte Madera, California, with 2-hour and 4-hour options. Teams of 1 to 5 use a custom map to locate up to 24 checkpoints scattered along trails and wild areas of the Tiburon Peninsula. The event emphasizes exploration and navigatio..

The Napa Lapa Trail Adventure in Skyline Wilderness Park, Napa, California, is Inside Trail Racing’s first time-based event, where runners go as far as possible in a fixed time. Distances include 12-, 6-, and 3-hour options, with each 4.16-mile loop delivering about 815 feet of elevation on fire roa..

The John Lawson Tamalpa Challenge is a three-race cross-country event held at Miwok Meadows in China Camp State Park, San Rafael, California. Each 4.2-mile course follows rolling single-track trails with about a quarter-mile on asphalt, starting near the Miwok Meadows gate and finishing in the Miwok..

The Diablo Summit Stomp is a Brazen Racing trail race in Walnut Creek, California, starting at Castle Rock Park and venturing into Mount Diablo State Park toward the summit. Runners can choose from four dirt-trail distances: 5K, 10K, Half Marathon, and 30K. The course features hills, potential mud a..