Thumbs Up Summer Slam
Estes Park, United States • 18 Jul 2026
Thumbs Up Summer Slam
Thumbs Up Summer Slam is a small-field endurance event held at the Thumb Open Space in Estes Park, Colorado on July 18, 2026. The race is limited to 30 participants and uses a short out and back trail repeated many times.
The course is a 1 km out and back with 540 ft of ascent per lap. At the turnaround each runner collects one poker chip and returns it to their assigned jar at the start area. Poker chips are counted at the end of the event to determine placing. Unique pins are awarded at three milestone totals and a special award is given to the overall winner.
Milestones:
- 14 ascents - Estes Park 7,522 ft
- 18 ascents - Deer Mountain 10,103 ft
- 26 ascents - Longs Peak 14,259 ft
The Thumb Open Space offers no participant parking. Organizers recommend arriving by bicycle or by drop off, and runners may leave supplies at the Start/Finish before the event. The preserved area opened to public access in July 2022 and is named for a thumb-shaped rock outcrop. Visit the organization's website for the most recent information.