50K Winter ultramarathons in California, United States

Classic Northern California terrain: flowing singletrack, rolling dirt paths, stout climbs, heat, exposure, and wide-open vistas.

Coastal trails through Point Mugu State Park, panoramic ocean views, rugged climbs, and rejuvenated landscapes with blooming flora

Loop through rolling Spangler Hills desert terrain on jeep roads, singletrack and sandy washes, with expansive views of the Southern Sierra.

Millerton Lake and San Joaquin River trails with scenic valley views, 50k route, regular aid stations, and crew access at River Gorge Management Area

No-frills urban ultramarathon from Twin Peaks with 50K or 50-mile routes through city landmarks, limited aid, and self-navigation challenges

Scenic 50K and Half Marathon with generous cutoffs, trekker-friendly course, and capped field for an intimate year-end event

Scenic and challenging trails in Orange County’s Chino Hills open-space park

Rugged dirt and rocky single-track trails through rolling hills, frequent ascents and descents, sweeping lake views, and minimal pavement at Cronan Ranch

Rolling hills and tree-covered trails through a 2,700-acre former Paramount Pictures expanse, with vibrant scenery and rugged terrain

Twisting singletrack through redwood groves, shaded canyons and ridge-top chaparral, with plenty of climbing and expansive Peninsula views.

Scenic trail routes through Hacienda Hills with Bay Area views and challenging elevation at Almaden Quicksilver County Park

Out-and-back ultra across Catalina Island with rugged terrain, Pacific Ocean views, and possible bison sightings from start and finish in Avalon.

Western States trail route featuring No Hands Bridge, K2 training hill, single-track along American River, Robie Trail, Dead Truck, Goat Hill, and Overlook Hill

El Dorado Trail route with stretches of pavement and rugged, unpredictable terrain; five minimal aid stations; self-supported format

Lush trails through Huddart Park, King's Mountain, and Bear Gulch surrounded by towering redwoods and dense ferns

95% single-track course along the Sweetwater Trail, winding through oak-dotted hills and Folsom Lake’s edge with Sierra foothill views

Rugged single-track trails and rolling hills on dirt ranch roads, significant elevation changes, panoramic West Cuesta Ridge views, historic barn setting

Rugged Santa Monica Mountains singletrack on the Backbone Trail, with ocean views and nearly 11,000 feet of climbing on the 50-mile course.

Trail route through Calico Ghost Town and Mining District, featuring rugged Calico Mountains terrain and historic mining landscapes.

Lakeside single-track and dirt roads at Lake Hodges, featuring varied terrain, scenic views, and challenging elevation gains in Southern California.