The Cliff Cave 50 Mile Challenge invites endurance enthusiasts to navigate through the rugged trails and limestone bluffs of Cliff Cave Park. This continuous race is part of The Next Loop Endurance Series, offering runners an immersive experience on a scenic 3.1-mile loop that winds its way through dense forests and rocky outcrops. Competitors will complete 16 laps over the course of approximately 50 miles, with each lap featuring fully stocked aid stations every five kilometers to ensure seamless access to fuel and hydration. The race is designed for strategic pacing, mental resilience, and continuous effort, culminating in a firm 12-hour cutoff that challenges runners to maintain steady energy levels throughout. Participants can stage their gear at either their vehicle or the designated athlete area within the park, allowing them to focus on dialing in their strategy lap by lap. Pacers are permitted after 4:00 PM, providing additional support as the race progresses into its later stages. The Cliff Cave 50 Mile Challenge caters specifically to ultra runners seeking a loop-based format with consistent aid station coverage and dedicated athlete staging areas. It is ideal for athletes who value pacing precision, strategic planning, and crew accessibility during long-distance events. With age group divisions available—Open, Masters (ages 50-69), and Grand Masters (70+)—the race offers a competitive yet supportive atmosphere tailored to the needs of endurance runners. This event promises raw, focused ultra experience where every loop is an opportunity for growth and achievement in one of Missouri's most picturesque trail settings.
Races Offered
40/50 Mile Challenge
Aug 22, 2026
straighten
Distance —
80.5K
terrain
Type —
Running
timer
4 days remaining
sell
$100.00
Weather History
These values represent the 3-year monthly averages for August in St. Louis.
thermostatTemperature
20.5° / 30.0°
wb_sunnyFeels like
21.8° / 31.1°
light_mode
Avg sunshine hours
11h 18m
water_drop
Avg rainfall
2.7 mm
ac_unit
Avg snowfall
—
air
Avg wind speed
8.9 km/h (Light breeze)
opacity
Sweat loss rate
Very high
terrain
Course conditions
Hard and dry surface
sunny
Max UV Index
High (7.0)
humidity_mid
Humidity
70.4%
wb_twilight
Sunrise
06:15
nightlight
Sunset
19:52
About St. Louis
Learn more about the host city, St. Louis.
The Gateway City of St. Louis is the epitome of the modern Midwestern metropolis. Missouri's second-largest city is vibrant but laid-back, populous but navigable, historic but still relevant. The city's planners have created an aesthetically beautiful city, with plenty of green space amidst buildings both old and new, framed by the majestic Mississippi and Missouri rivers. And capping it all is the world's tallest man-made monument, the beautiful and iconic Gateway Arch.