Ouray 100 Mile Endurance Run

2026

The Ouray 100 takes place in mid-July in the San Juan Mountains of southwest Colorado, covering roughly 102 miles with a generous 52-hour time limit. This high-altitude adventure features an out-and-back format with multiple visits to several aid stations, including repeated stops at key points like Fellin Park and strategic turnarounds at locations such as Crystal Lake and Weehawken. The course winds through classic Colorado mountain terrain, moving between historic mining areas and alpine environments around the Ouray region. Runners can expect significant elevation changes as the route ventures toward places like Camp Bird and Ironton, with stretches that likely include both technical single track and old mining roads. At this elevation and in mid-July, afternoon thunderstorms are common, and temperatures can vary dramatically between exposed ridgelines and shaded valley sections. Pacers are permitted starting at mile 53.7, which suggests the latter half presents the more challenging terrain or navigation. Runners comfortable with long mountain efforts, changing weather conditions, and the mental challenge of retracing sections of course will find this race appealing. The 52-hour cutoff provides room for hiking the steeper climbs, but the combination of altitude, distance, and mountain weather means this isn't a race for those new to high-altitude ultras.