Relay ultramarathons in California, United States

Scenic loop route on dirt fire trails with modest elevation gain and classic trail ambiance

Time-based ultrarun in Napa's Skyline Wilderness Park, 4.16-mile trail loop with 815 feet of gain per lap through rolling hills and historic landscapes

Scenic 2-mile loop at Harvey Bear Ranch with hill and mountain views, multiple distance options, generous cutoff times, and a community-focused environment.

Looped 0.85-mile paved bike path through scenic Auburn, with picturesque ponds, shaded stretches, and multiple distance options

50-mile route from Norco to Huntington Beach, traversing diverse Southern California landscapes with scenic beauty and rugged terrain

Self-supported fundraising run with 5K and 10K options, virtual or at San Francisco Ferry Building, featuring a scenic unmarked course

Food trucks, fitness activities, live music, and wellness expo alongside family-friendly entertainment zones

USATF-certified 1.0-mile loop around Cottonwood Lake with lake views, challenging endurance events including 24 Hour Solo and 100 Mile distances

24-hour format on the rugged Molcajete 1.0 loop, repeated again and again for a climbing-heavy endurance test.

Rugged 50K in Angeles National Forest with 9,000+ feet of climbing and descending on mostly dirt trails through steep canyon terrain.

Rugged loop course through Goodan Ranch Sycamore Canyon Preserve, varied natural terrain and canyon views just east of San Diego.

62-mile course in the Marin Headlands, over 11,000 feet of elevation, single-track trails and dirt roads, views from redwoods to coastal cliffs

Flat 1-mile dirt and grass loops on a private horse ranch in Riverside, lap-based ultra with accessible support and camping options for families and crews