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 River Bluff Trail. Competitors run repeated laps of a clearly marked 3.1 mile (5K) loop that returns to the same central start and finish area and a fully stocked aid station every lap.
The trail surface is primarily packed dirt with sections of crushed limestone and natural singletrack. The route includes roots, short climbs, limestone bluffs, and river overlooks. Elevation is more pronounced than flatter park courses, featuring rolling hills and bluff-side sections that require attention on technical areas while still allowing consistent lap running.
Support and logistics are centralized at the loop. Runners may access personal supplies at a designated staging area each lap. Crew access is permitted in designated areas and pacers are allowed according to event rules. Medical and race staff are on site throughout the event. The format aims to simplify logistics by keeping aid, staging, and support at a single location so athletes can refuel, change gear, and rest without leaving the course.
Event details include a 12 hour time limit and separate scoring from the concurrently held Next Loop Endurance Series, which runs on the same course with an hourly format. Registration is limited to preserve course quality and runner support.
Distances: Visit the organization's website for the most recent information.
- 40 Mile
- 50 Mile