Rio Grande 100
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About the race
Rio Grande 100, staged in South Fork, Colorado, starts and finishes on the banks of the Rio Grande River. The 100‑mile ultramarathon traverses the La Garita mountains, shifting from arid forest to alpine tundra as runners reach elevations above 12,000 feet four times. Expect golden aspen leaf trails, plenty of rocks, and a rugged, high‑country vibe.
The event emphasizes safety and crew support, with weather preparedness critical for a late‑season race that can be exceptionally challenging. Past weather challenges, including a 2022 snowstorm that canceled the race mid‑event, prompted safety‑focused changes. It is part of Tempest Adventures Triple Crown, linking Mace's Hideout 100 and Creede 100. Visit the organization's website for the most recent information.