40/50 Mile Challenge - Cliff Cave
Oakville, United States • 22 Aug 2026
40/50 Mile Challenge - Cliff Cave
The event is a continuous loop trail race held at Cliff Cave Park on a clearly marked 3.1-mile (5K) loop. The course follows the River Bluff Trail and passes wooded hillsides, limestone bluffs, and overlooks of the Mississippi River. Trail surfaces include packed dirt, crushed limestone, and natural singletrack with roots, short climbs, and a few technical sections. Elevation is more pronounced than flatter park courses, with rolling hills and bluff-side sections.
The format is continuous running until a chosen distance is reached or the time limit expires. The time limit is 12 hours. The start and finish are at the same central location each lap, and a fully stocked aid station is available on every loop. Runners may access personal supplies at a designated staging area near the start/finish. Crew access is permitted in designated areas and pacers are allowed per event rules. Medical and race staff are on site throughout the event.
The 40/50 Mile Challenge runs alongside The Next Loop Endurance Series on the same loop. Next Loop participants run on the hour while 40/50 Mile Challenge competitors run continuously and are scored separately. Registration is limited to maintain course quality and support.
Distances offered:
- 40 Mile
- 50 Mile
Location: Cliff Cave Park, 806 Cliff Cave Rd, St Louis, MO 63129 Visit the organization's website for the most recent information.