100mi ultramarathons in California, United States

Remote San Gabriel backcountry route through preserved wilderness, featuring picnic spots, campgrounds, and a demanding 100-mile ultrarunning course

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

Rugged 100-mile route through the San Gabriel Mountains' primitive wilderness, featuring rough terrain and scenic, largely untouched backcountry

Mountain routes near Los Angeles featuring Big Bear Lake views, Sugarloaf Mountain ascents, and descents into Siberia Canyon

Rugged Lake Sonoma trails with 24,000 feet of elevation gain, fast non-technical sections, winter mud and rain, vibrant start/finish festivities

2-mile double track dirt loop with 128 feet of gain per lap, mountain desert scenery, starlit night running, camping on-site, real bathrooms and aid station

Rugged Los Padres trails over the Gaviota Coast with steep climbs, panoramic ridgelines, ocean and island views, and up to 25,000 feet elevation gain

Rugged loops around Lake Perris with 2,300 to 4,500 feet of elevation gain, lake and mountain views, frequent aid stations, and camping on site

Brutal, breathtaking 200-mile route featuring over 44,000 feet of climbing and a 96-hour cutoff through some of the USA's toughest terrain

Undulating course through Western States trails, with Folsom Lake and American River views across single track and roads in Northern California

Flat 1-mile loop on 100% hardpacked dirt, set on a Southern California fruit and nut farm with close access to aid, crew, and vehicles.

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

Rolling 2-mile loops through Will Rogers State Park, gentle terrain, multiple laps, fully stocked aid station, solo and relay formats, 24- and 12-hour options

Scenic lap course through Reedley farmland, orchards, vineyards, and along the Kings River, racing from sunset through moonlit night to dawn

Looped course at Cesar Chavez Academy in south Corona foothills, with options for 1/4 or 1-mile loops and scenic day and night views

50-mile trail ultra in Angeles National Forest near Lake Hughes, crossing the Leona Divide twice and spending time on the Pacific Crest Trail.

Rugged Sierra Nevada foothills, historic gold-rush routes, steep canyons, and challenging scenic terrain through the birthplace of mountain ultras

Demanding mountain loop featuring 15,400 feet of elevation change, technical single track, and arid conditions through Cuyamaca and Anza Borrego State Parks