Colorado Ultramarathons
62 upcoming ultras across Colorado, updated nightly. Want radius search and maps? Open these in the Race Finder.
When to race: ultras in Colorado
Colorado has 62 upcoming ultras over the next 12 months. September is the busiest month for them, with 24. Most are around Colorado Springs, Estes Park, Crested Butte. The next one is Front Range Ultra Dayze on September 4 in Loveland.
- Sep 202624 races
- Oct 202612 races
- Nov 20264 races
- Dec 20262 races
- Apr 20273 races
- May 20275 races
- Jun 20274 races
- Jul 20275 races
- Aug 20273 races
September 2026
- Fri 9/4Front Range Ultra DayzeLoveland, CO · 2 Mile · 200 Miles · 100 Mile · 50K · registration closed · register ↗
- Sat 9/5Front Range Ultra DayzeLoveland, CO · Ultra · register ↗
- Sat 9/5Creede Mountain RunCreede, CO · 50K · 22 Miles · 12 Miles · 2 Mile · Trail · register ↗
- Sat 9/5The Grand TraverseCrested Butte, CO · 40 Miles · 80 Miles · from $205 · registration closed · register ↗
- Fri 9/11American Heroes RunLongmont, CO · 100 Mile · 24 Hour · 6 Hour · register ↗
- Fri 9/11Flaming Foliage Relay - Idaho Springs to Buena VistaIdaho Springs, CO · 165 Miles · from $623 · register ↗
- Sat 9/122026 Lake Nighthorse Triathlon - Sprint and OlympicDurango, CO · 25.75K · 51.5K · from $85 · register ↗
- Sat 9/12Devil on the DivideEmpire, CO · 50K · 22K · register ↗
- Sat 9/12Rampart Rager GravelColorado Springs, CO · 32 Miles · 44 Miles · 100K · 11.5 Miles · from $59 · register ↗
- Sat 9/12Snow Mountain RanchGranby, CO · 50K · 33K · Half Marathon · 10K · 5K · Trail · register ↗
- Sat 9/12The Gunni GrinderGunnison, CO · 120 Miles · 60 Miles · 30 Miles · from $60 · register ↗
- Fri 9/18Run Rabbit RunSteamboat Springs, CO · 100 Mile · register ↗
- Sat 9/19Beulah Challenge and OverIt SeriesBeulah, CO · 10K · 5K · 32.4 Miles · from $20 · register ↗
- Sat 9/19Salida Bike Fest - Salida 76 and the Banana BeltSalida, CO · 76 Miles · 76K · 35 Miles · from $125 · register ↗
- Wed 9/23CG Adventure Club - Elevation EverestWinter Park, CO · 22 Miles · 42 Miles · from $150 · registration closed · register ↗
- Fri 9/25Red Feather Trail JamboreeRed Feather Lakes, CO · 50 Mile · 50K · Half Marathon · 94 Miles · Trail · from $90 · register ↗
- Sat 9/2624 Hours of Palmer LakePalmer Lake, CO · 24 Hour · register ↗
- Sat 9/26Crested Butte UltraCrested Butte, CO · 50 Mile · 55K · 35K · register ↗
- Sat 9/26Estes EpicEstes Park, CO · 50K · 15 Miles · 100K · from $105 · registration closed · register ↗
- Sat 9/26Mountains to the Desert ClassicTelluride, CO · 103 Miles · 73 Miles · 110 Miles · from $185 · register ↗
- Sat 9/26Sangre de Cristo Trail FestivalWestcliffe, CO · 8 Miles · 27K · 50K · 50 Mile · 100K · Trail · from $40 · register ↗
- Sat 9/26WILD Wahatoya RunsLa Veta, CO · 50K · Half Marathon · 8 Miles · register ↗
- Sat 9/26West Line WinderBuena Vista, CO · 50K · 30K · from $105 · register ↗
- Sun 9/27Sawatch AscentNathrop, CO · 50K · from $129 · register ↗
October 2026
- Sat 10/3Above the Clouds UltraWoodland Park, CO · 50K · 10K · register ↗
- Sat 10/3Grand Valley BackyardLoma, CO · Timed · register ↗
- Sat 10/3Sage Burner Trail RaceGunnison, CO · 50K · 28K · 15K · Trail · register ↗
- Sat 10/3The Bear ChaseLakewood, CO · 100K · 50 Mile · 50K · register ↗
- Sat 10/10Grassroots GravelPueblo, CO · 110 Miles · 75 Miles · 40 Miles · 15 Miles · 19 Miles · register ↗
- Sat 10/10Rocky's Backyard UltraEstes Park, CO · Timed · register ↗
- Sat 10/10Suffer Better 10th Annual Fall Trail RunsPine, CO · 50K · 25K · 5K · Trail · from $25 · register ↗
- Sat 10/17Bobcat Trail RacesColorado Springs, CO · 50K · 25K · 10K · 5K · Trail · register ↗
- Sat 10/17Indian Creek Trail RunsSedalia, CO · 5.5 Miles · 15 Miles · 35 Miles · 54 Miles · Trail · from $30 · register ↗
- Sat 10/24Bridge Burner UltraCanon City, CO · 35 Miles · 50K · 35K · 10K · register ↗
- Sat 10/24The Barnyard Backyard UltraErie, CO · Timed · register ↗
- Sat 10/31Bear Creek Backyard UltraLakewood, CO · Timed · register ↗
November 2026
- Sat 11/7Colorado 24 Hour RunFort Collins, CO · 24 Hour · 12 Hour · 6 Hour · from $90 · register ↗
- Sat 11/7Kessel Run UltraFruita, CO · 50 Mile · 40 Miles · 50K · 20 Miles · 10 Mile · register ↗
- Sat 11/7Sandstone SixerLarkspur, CO · 6 Hour · register ↗
- Sat 11/21Colorado Cold Rush UltraColorado Springs, CO · 50K · Half Marathon · 10K · register ↗
December 2026
- Sat 12/5Sawmill Trail RunsPine, CO · 8.1 Miles · 16.1 Miles · 31.7 Miles · Trail · from $60 · registration closed · register ↗
- Sat 12/5Thumbs Up Vertical ChallengeEstes Park, CO · 8 Hour · register ↗
April 2027
- Sun 4/11NoCo Urban Ultra & RelayBellvue, CO · 50 Mile · 100 Mile · from $65 · register ↗
- Sat 4/17Rattler Trail RaceColorado Springs, CO · 50K · 25K · 10K · 5K · Trail · register ↗
- Sat 4/24Cheyenne Mountain Trail RaceColorado Springs, CO · 50K · 25K · 7 Miles · 4 Miles · Trail · register ↗
May 2027
- Sat 5/1Greenland Trail RacesLarkspur, CO · 50K · 25K · 8 Miles · 4 Miles · Trail · from $25 · register ↗
- Sun 5/2The PilgrimageMack, CO · Ultra · register ↗
- Sat 5/8Adventure Fest at 18 RoadFruita, CO · Ultra · register ↗
- Sat 5/8Valkyrie Trail RaceColorado Springs, CO · 50K · Marathon · 30K · Half Marathon · 8 Miles · Trail · register ↗
- Sat 5/22Samson's RevengeEstes Park, CO · 10.45K · 25K · 50K · from $112 · registration closed · register ↗
June 2027
- Sat 6/5Weld Your Mettle Running FestivalEaton, CO · 50 Mile · 100K · 4.3 Miles · 14 Miles · Marathon · from $35 · register ↗
- Sat 6/12KowTown GravelKremmling, CO · 88 Miles · 54 Miles · 28 Miles · 16 Miles · from $85 · registration closed · register ↗
- Sat 6/12Summits Trail RunsGranby, CO · 10K · 13.9 Miles · 27.8 Miles · 33.9 Miles · Trail · from $60 · registration closed · register ↗
- Fri 6/25Race in the Clouds - Alma Dirt Festival 2027Alma, CO · 38 Miles · Marathon · Half Marathon · 22 Miles · 10K · from $10 · register ↗
July 2027
- Fri 7/9Hardrock 100 Endurance RunSilverton, CO · 100 Mile · register ↗
- Fri 7/9Silverheels Trail RunsComo, CO · 10.8 Miles · 19.1 Miles · 38.3 Miles · 53.8 Miles · 63.1 Miles · Trail · from $60 · registration closed · register ↗
- Fri 7/16Ouray 100 Mile Endurance RunOuray, CO · 100 Mile · register ↗
- Sat 7/24Pikes Peak UltraColorado Springs, CO · 50 Mile · 50K · 30K · 20K · register ↗
- Mon 7/26The Summit 200Frisco, CO · Ultra · register ↗
August 2027
- Fri 8/6Wild West RelayFort Collins, CO · 200 Miles · from $700 · register ↗
- Sat 8/7Sheep Mountain Trail RunsFairplay, CO · 14.2 Miles · 33 Miles · 53.1 Miles · Trail · from $80 · registration closed · register ↗
- Sat 8/7Winter Park Trail RunsWinter Park, CO · 50K · Half Marathon · 10K · Trail · register ↗
Planning a race
- The adventure listrim to rim, the big rounds, and routes worth planning a year around
- Getting inhow entry works for the races that sell out or ballot
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