100mi ultramarathons in United States (West) in 2027

Desert singletrack and foothill paths in Estrella Mountain Regional Park, with Sonoran scenery and 100K or 100-mile options.

Rugged mountain trails above Honolulu with steep climbs, technical terrain, tropical forest, and panoramic Pacific Ocean views

Rugged Nevada desert ultra on a demanding 12.5-mile loop: 90%+ singletrack, technical terrain, steep climbs, fast descents, and Black Mountain.

Multi-distance looped course connecting Bainbridge Island’s top public and private trail networks, with February weather and minimal road segments

10-mile desert loop with steep climbs and descents, packed dirt and rocky terrain, elevations from 1903 to 2333 feet, expansive mountain and desert views

100-mile marked winter loop through frozen rivers, swamps, and wooded trails with mountain views, possible aurora sightings, and wildlife encounters

Certified 1.2-mile loop with gentle elevation, 95% hard surface, scenic lake and bridge crossings, and generous time limits in Henderson, Nevada

Remote Arizona Strip loop on ATV trails through rocky canyons and Joshua tree country, with steep climbs, rugged footing, and wide-open views

100.8-mile Orcas Island loop with steep singletrack, mountain lakes, ancient forests, Salish Sea views, and 26,000 feet of elevation gain

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

Rugged Wyoming wilderness, snow-covered trails, subfreezing temperatures, ski, bike, or run routes inspired by historic cattle drives

Flat, scenic dirt trail loop at Eagle Island State Park near Boise, Idaho

Badger Mountain Preserve trails with wide-open terrain and sweeping Columbia Basin views in Richland.

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

Double out-and-back course across asphalt, gravel, and dirt trails with over 10,000 feet of gain through Oregon parkland and small-town landscapes

105-mile point-to-point on remote singletrack through southern Arizona, with 12,500+ ft of climbing across desert, oak woodlands, and mountain terrain.

Remote Alaska winter ultra amid jagged limestone peaks, with steep climbs, glare ice, drifting snow, and constantly changing trail conditions.

Southern Utah desert course with mesa ascents, panoramic views, and technical terrain near Zion National Park

Ultra-distance courses along the Poudre River Trail from Watson Lake to Greeley, featuring scenic Northern Colorado landscapes and aid stations.

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