September ultramarathons in California, United States

Mountain vistas, dirt trails, and rugged climbs at China Peak Mountain Resort; options for 25km, 50km, and 100km distances

Mountain trails through east San Diego County, runnable single-track, National Forest scenery, challenging terrain, 9.5-hour cutoff

Scenic 50K trail course with multiple aid stations, well-maintained paths, and festive post-race refreshments

Mount Diablo course featuring panoramic vistas of the San Francisco Bay Area and surrounding valleys, emphasizing the region’s natural scenery

Trail route through Mendocino Woodlands State Park with forest scenery, tent cabin options, and meals included on Saturday

Scenic trails through Tilden Regional Park and Wildcat Canyon, shaded oak and eucalyptus groves, open stretches with bay and bridge views, beginner-friendly

Single-track trails, steep hills, oak woodlands, open heat-exposed stretches, panoramic views; 50K course suitable for Western States preparation

4.18-mile dirt loops each hour on trail and ranch roads, 332 feet of elevation change per lap, last-runner-standing format

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

1-mile loop on private desert land near Joshua Tree, 12-hour format, high desert scenery, festive atmosphere, well-stocked aid each lap

10 km dirt singletrack loop on a private cattle ranch, moderate climbs and sweeping views, well-stocked aid stations, overnight camping and evening bonfires

Diverse 50k route through Cheesebro Canyon, steep climbs, runnable ascents, winding singletracks, major elevation changes, and expansive canyon views

San Gabriel Mountain routes with 50K and 60K options, 5700 to 7400 feet of gain, final climb on Kenyon Devore Trail to Mt Wilson summit

Rocky Peak, Las Llajas, and Tapo Canyon mountain trails from historic Corriganville Park with city and ocean views and challenging elevation gains

Bay Ridge 100k and Firetrails 50-mile ultras commemorating Dick Collins, featuring P-USATF Grand Prix competition and UTMB points eligibility

Rocky 3.3-mile loops with 550 feet of elevation gain, shaded trails, alternating directions, and a grassroots backyard format in Napa’s Skyline Wilderness Park.

Technical single-track and well-maintained paths through Angeles National Forest, with mountain vistas and demanding Southern California terrain

Steep, well-maintained trails winding through coastal redwood groves, significant climbs and descents, shaded singletrack in the Santa Cruz Mountains