40/50 Mile Challenge - Cliff Cave
Oakville, United States • 22 Aug 2026
40/50 Mile Challenge - Cliff Cave
The 40/50 Mile Challenge is a continuous loop trail race held at Cliff Cave Park on the same 3.1 mile (5K) loop used by The Next Loop Endurance Series. Unlike the hourly format of the series, competitors in this event run continuously and are scored separately.
The loop runs through wooded hillsides and along limestone bluffs with overlooks of the Mississippi River. The course is clearly marked and returns each lap to a central start and finish area with a fully stocked aid station. Trail surfaces include packed dirt, sections of crushed limestone, and natural singletrack with roots, short climbs, and a few technical areas. Elevation is more pronounced than flatter park courses, featuring rolling hills and bluff side sections.
Logistics support is centralized. Runners may access personal supplies at a designated staging area each lap. Crew access is permitted in designated areas and pacers are allowed under event rules. Medical and race staff are on site. The event uses a 12 hour time limit so runners complete repeated laps until they reach their chosen distance or the cutoff. Registration is limited to preserve course quality and runner support.
Distances offered: Visit the organization's website for the most recent information.
- 40 Mile
- 50 Mile