Cirque Series - Arapahoe Basin
Keystone, United States • 5 Sep 2026
Cirque Series - Arapahoe Basin
The event on September 5, 2026 at Arapahoe Basin, Colorado, is a mountain trail race of 9.4 miles with 2,211 ft of vertical gain. The field is capped at 700 runners.
The course begins at Mountain Goat Plaza at 10,780 ft and follows the A-Basin summer road to Black Mountain Lodge. Runners traverse terrain that includes a new singletrack hiking section near the top of the Pali lift, Zuma Cornice, a service road to the saddle, and the top of the Montezuma lift before continuing on the Lenawee trail to Little Lenawee summit. The route then descends, joining the Half Moon Vista high alpine trail and the Argentine North Fork singletrack, finishing on a new mountain bike singletrack into Mountain Goat Plaza.
The course is located on approved established trails in the White River National Forest and may be adjusted as necessary. Every runner is subject to a strict cutoff at Black Mountain Lodge Aid Station #1 of 30 minutes.
Organizers note that the route is steep and will be well marked. Runners should follow flagging precisely and use careful footwork in technical sections. On Little Lenawee summit sections, competitors are instructed to shout "rock" if they dislodge a rock; others who hear "rock" should protect their head and avoid looking uphill.
Early bib pick up is scheduled for Friday, September 4, 2026 in Boulder at the La Sportiva retail store. Each competitor receives a snapback, giveaway ticket, logoed bib and medal, a sponsor swag bag, and free professional photos. The finish area at Mountain Goat Plaza will feature live music and food. Visit the organization's website for the most recent information.