40/50 Mile Challenge, Cliff Cave St. Louis

The course at Cliff Cave Park, featuring the River Bluff Trail, offers a scenic and moderately challenging route that winds through wooded hillsides, limestone bluffs, and overlooks of the Mississippi River. Runners will complete a clearly marked 3.1-mile (5K) loop, returning each lap to the same central start/finish area and fully stocked aid station.​

The trail surface is primarily packed dirt with sections of crushed limestone and natural singletrack, including roots, short climbs, and a few technical areas that add variety. The elevation is more pronounced than flatter park courses, with rolling hills and bluff-side sections that provide a rewarding challenge without being overly difficult. While still accessible to newer trail runners, the terrain offers enough complexity to keep experienced runners engaged over multiple loops.​​

With scenic river views, dense forest coverage, and a true trail-running feel, the loop-based format allows runners to manage effort, refuel efficiently, and choose their distance as they go. Whether tackling a single lap or building toward a longer endurance effort, Cliff Cave Park delivers a balance of natural beauty, dynamic terrain, and convenient race support for athletes of all levels.