Ultramarathons in Colorado

Saturday, September 12 · Granby, Colorado

The Snow Mountain Ranch 50K takes place in September at the YMCA of the Rockies near Granby, Colorado. This is a three-loop format covering roughly 31 miles, with each 10.4-mile loop gaining about 1,400 feet of elevation for a total of 4,236 feet of climbing. The course runs entirely on dirt trails and reaches a maximum elevation of 9,844 feet. Each loop features a sustained climb from miles 3-6, which becomes a significant mental and physical challenge as fatigue builds through the day. The route moves through high-altitude terrain with three aid stations per loop, and runners must start their final loop by the 6-hour mark to finish within the 8.5-hour cutoff. September weather at this elevation can be unpredictable, so layers are typically necessary for the early morning start. This race suits runners comfortable with sustained climbing at altitude and the mental demands of repetitive loops. The relatively short loops mean you'll see the start/finish area frequently, which some find motivating and others find taxing. If you struggle with altitude or prefer varied scenery throughout a long race, this might not be your best fit. Pacers are allowed on the final loop only, starting around mile 21.

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.