Colorado Mountain Half+ Series

Keystone, United States • 21 Jun 2026

Colorado Mountain Half+ Series 2026

The Colorado Mountain Half+ Series consists of five distinct distance running events held across various mountainous locations in Colorado. Participants have the option to register for a bundle of three, four, or all five events. Each race in the series is organized by a nonprofit organization dedicated to supporting local youth programs.

The series includes four half marathons and one 25 km distance. The individual events are scheduled as follows:

  • Estes Park Half Marathon: This race takes place at the base of Rocky Mountain National Park. The course is set within a mountain landscape known for its resident elk herd.
  • Georgetown to Idaho Springs Half Marathon: This event follows a mostly downhill course. It begins at Georgetown Lake and concludes in Idaho Springs.
  • Mt. Sneffels Half Marathon: Located in an area referred to as the Switzerland of America, this race features a declining course through a valley with views of surrounding mountain ranges.
  • Ned-Ned Half Marathon: This trail-based event is held in Nederland. The route passes through national forests and utilizes Barker Reservoir as a backdrop.
  • Lead King Loop 25K: Representing the "+" in the series title, this 15.5 mile course takes place in September. The event includes a post-race barbecue.

Participants can earn points at each race toward series awards. Registration is available for teams or individuals, and gift registrations are also supported. The series covers a total of approximately 67.9 miles for those completing all five events. Visit the organization's website for the most recent information.

Race information

25 km
Lead King Loop 25k
13 mi
Mt. Sneffels Half Marathon
13 mi
Ned Ned Half Marathon
13 mi
Georgetown to Idaho Springs Half Marathon
13 mi
Estes Park Half Marathon
Visit the organization's website for the most recent information.
Trail runs nearby

A 20K loop around Turquoise Lake in Leadville, CO, running clockwise with hilly paved road then single-track trail. Proceeds support Leadville youth athletics; adult entry is $40 and youth 17 and under enter free.

A 5K trail run at the Leadville National Fish Hatchery on May 31, 2026, with a cross country style route through subalpine forest around Evergreen Lakes and lower Rock Creek. Proceeds support Leadville youth athletics and recreation.

Six trail races across Summit County, Colorado, in summer 2026. Series registration includes long and short course options with adult, youth, and non binary categories and events at multiple Summit County trail heads.

Prepare for the Race Across the Sky at this three day training camp in Leadville. Run key sections of the 100 mile course alongside veteran guides and attend educational panels on nutrition and biomechanics.