Ultramarathons in Colorado

Friday, July 17 · Ouray, Colorado

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.

Saturday, September 26 · Palmer Lake, Colorado

The 24 Hours of Palmer Lake is a timed ultramarathon where runners complete as many laps as possible on a short 0.82-mile loop course over 24 hours, from 8 AM Saturday to 8 AM Sunday. Set at 7,240 feet elevation on Colorado's Palmer Divide, the course offers mountain views but little variation in terrain or scenery as you circle the same route dozens of times. The format strips away most trail running variables—no navigation, minimal elevation change per loop, and constant access to crew support and aid at the single station. What remains is a pure test of endurance and mental fortitude as you rack up miles in short increments. The high altitude adds a cardiovascular challenge, especially for runners not accustomed to elevation, while the repetitive nature can be either meditative or maddening depending on your mindset. This race appeals to runners looking to test distance limits without technical terrain, those training for longer events, or anyone curious about the mental game of loop running. If you need varied scenery or challenging terrain to stay engaged, the repetitive nature might feel tedious. Runners comfortable with their own thoughts and motivated by accumulating miles will find this format oddly compelling.