Rocky Mountain Slam
Logan, United States • 25 Sep 2026
Event Overview
The Rocky Mountain Slam (RMS) is a series of 100-mile ultramarathon races in the Rocky Mountains. It is not a single race, but a challenge where runners must complete four qualifying races. The Bear 100 is the only mandatory event, serving as the series finale.
History and Format
The series originated in the early 2000s to create a mountain-focused counterpart to other endurance series. The format was updated for 2022 (V2.0) due to increased difficulty gaining entry into the original races via lottery. This new format offers runners more flexibility in choosing their qualifying events.
Race Series Details
Runners must complete four 100-mile races total. Participants choose three optional races from a list that includes:
- Scout Mountain 100
- Bighorn 100
- Hardrock 100
- Leadville 100
- Wasatch Front 100
- Ouray 100
- Wyoming Range 100
- High Lonesome 100
- Crazy Mountain 100
The fourth and mandatory race is The Bear 100. The races are held from June through September. There is a separate registration and fee to officially enter the Rocky Mountain Slam series, which covers organizational costs and a finisher award. Runners are responsible for securing entry into the individual races, many of which use lottery systems. Visit the organization's website for the most recent information.