Ultramarathons in Colorado
Discover ultramarathon and trail running races across Colorado. Browse upcoming events, view course maps, and explore race results.
Race The Ranch 50K
Race The Ranch 50K is a snowshoe race held each April at Snow Mountain Ranch YMCA in Granby, Colorado. The course covers four laps of roughly 7.5 miles each, with about 2,200 feet of total elevation gain spread across singletrack, doubletrack, and groomed snowshoe trails around the property's less-traveled routes. April snowshoeing in Colorado means variable conditions — you might encounter everything from packed powder to spring slush depending on recent weather and time of day. The course can be modified leading up to race day based on trail conditions, so expect some uncertainty in your final route planning. Each lap brings you back through the start/finish area and past the on-course aid station at roughly mile four, making it easy to adjust gear or refuel as conditions change. This race suits snowshoe runners comfortable with lap formats and changing spring mountain conditions. The 10-hour cutoff is generous for most experienced ultrarunners, but factor in the energy cost of snowshoeing and potentially soft or technical snow conditions. If you prefer predictable courses or haven't spent much time on snowshoes, the shorter 25K option might be a better starting point.
24 Hours of Palmer Lake
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.