Colorado Mountain Half+ Series
Keystone, United States • 21 Jun 2026
Event Overview
The Colorado Mountain Half+ Series is a collection of five distinct running events. The series includes four half marathons and one 25K race, totaling approximately 67.9 miles.
Event Locations & Dates
The series takes place at multiple locations across Colorado from June to September 2026. The individual events are scheduled as follows:
- Estes Park Half Marathon on June 21
- Georgetown to Idaho Springs Half Marathon on August 8
- Mt. Sneffels Half Marathon on August 15
- Ned Ned Half Marathon in Nederland on September 12
- Lead King Loop 25K (15.5 miles) on September 13
Course Details
Each event has a unique course. The Estes Park race is part of a marathon weekend and takes place at the base of Rocky Mountain National Park. The Georgetown to Idaho Springs course is described as mostly downhill and fast. The Mt. Sneffels and Ned Ned events feature trails and scenic mountain valley routes. The series-concluding Lead King Loop 25K is noted for its fall colors.
Registration Options
Participants can register for a 3-event pack, a 4-event pack, or the full 5-event series. The events are organized by nonprofit groups that support local youth programs. Visit the organization's website for the most recent information.