40/50 Mile Challenge - Deer Grove East
Deer Park, United States • 8 Aug 2026
40/50 Mile Challenge - Deer Grove East
The 40/50 Mile Challenge is a continuous loop endurance race held at Deer Grove East Forest Preserve in Palatine, Illinois. The event offers two distance options and uses a 3.1 mile loop that returns each lap to the same centralized start and aid area.
- 40 Mile
- 50 Mile
The course runs through restored prairie, open wetlands, oak savannas, and shaded woodland corridors. Trails are primarily flat to gently rolling and include a mix of paved and natural surfaces. Open sections provide views across prairie and wetland habitats while wooded sections offer periodic shade.
Each lap brings runners back to a fully stocked aid station and a designated personal staging area. 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. There is a 12 hour time limit; runners complete repeated loops until they reach their chosen distance or the time limit expires.
The format is presented as a continuously running loop with centralized support. The setting at Deer Grove East includes restored grasslands and wetland habitats where runners may encounter deer, native birds, and seasonal wildflowers while on course. Visit the organization's website for the most recent information.