Trail running course through singletrack trails in Missouri, USA
Ozark Foothills Endurance Runs

Ozark Foothills Endurance Runs — 100K

100K·6,132 ft gain·Wildwood, Missouri
ultra100kforesttechnicalnighttrailloop

AI-generated image

Distance100K
Gain6,132 ft
DateApr 11, 2026
Difficulty4/5

About This Race

The 100K option provides a substantial ultra challenge without the full commitment of the 100-mile distance, typically finishing before the deepest night hours. This distance attracts runners looking to step up from 50-mile racing or those seeking a challenging day-long effort in the Missouri woods. The course demands respect for its technical sections and rolling nature, making it an ideal proving ground for runners building toward longer ultra distances.

The race follows a looped course through Greensfelder County Park's trail system, showcasing some of the region's most challenging and scenic terrain. Runners navigate more than 80 percent singletrack trails that wind through the foothills of the Ozark Mountains, encountering everything from steep climbs to rolling descents. The technical nature of the course, with its mix of roots, rocks, and varied elevation changes, requires runners to stay present and engaged throughout their effort.

The terrain ranges from demanding steep grades that test climbing strength to flowing singletrack sections that reward rhythm and flow. This variety keeps the course interesting across multiple loops while providing different challenges as fatigue sets in during longer distances.

Elevation Profile

Elevation profile estimated from terrain data. Actual course may differ.

The course gains 6,132 ft over 62 miles, with the steepest section between mile 26–mile 26.

Location

Practical Info

Weather

April in Missouri typically offers mild spring conditions with temperatures ranging from the 40s to 70s Fahrenheit, though runners should prepare for potential rain and variable conditions.

Nearest Airport

STL - Lambert-St. Louis International Airport

Accommodation

The race partners with Drury Inn & Suites St. Louis Southwest (15 minutes from the start) for group rates. Greensfelder County Park offers tent camping and RV hookups with showers. Additional lodging options available in Wildwood, Ballwin, Fenton, Chesterfield, and Ellisville.

Best For

Experienced trail runnersUltra runners seeking technical terrainRunners wanting a supportive community atmosphere

Notable Features

The Ozark Foothills stands out for its commitment to diversity and inclusion through the Trail Mix Fund partnership, which waives registration fees for BIPOC and LGBTQ+ runners or those facing financial barriers. The race also features a unique 500 Miles Club for repeat participants and offers a rare night 50K option alongside traditional distances. The technical, root-and-rock-filled singletrack provides a genuine challenge while the looped format creates excellent spectator and crew access opportunities.

Other Distances at This Event

25K

3,442 ft gain

The race follows a looped course through Greensfelder County Park's trail system, showcasing some of the region's most challenging and scenic terrain. Runners navigate more than 80 percent singletrack trails that wind through the foothills of the Ozark Mountains, encountering everything from steep climbs to rolling descents. The technical nature of the course, with its mix of roots, rocks, and varied elevation changes, requires runners to stay present and engaged throughout their effort. The terrain ranges from demanding steep grades that test climbing strength to flowing singletrack sections that reward rhythm and flow. This variety keeps the course interesting across multiple loops while providing different challenges as fatigue sets in during longer distances.

25K Ruck

3,442 ft gain

The race follows a looped course through Greensfelder County Park's trail system, showcasing some of the region's most challenging and scenic terrain. Runners navigate more than 80 percent singletrack trails that wind through the foothills of the Ozark Mountains, encountering everything from steep climbs to rolling descents. The technical nature of the course, with its mix of roots, rocks, and varied elevation changes, requires runners to stay present and engaged throughout their effort. The terrain ranges from demanding steep grades that test climbing strength to flowing singletrack sections that reward rhythm and flow. This variety keeps the course interesting across multiple loops while providing different challenges as fatigue sets in during longer distances.

Marathon

5,823 ft gain

The race follows a looped course through Greensfelder County Park's trail system, showcasing some of the region's most challenging and scenic terrain. Runners navigate more than 80 percent singletrack trails that wind through the foothills of the Ozark Mountains, encountering everything from steep climbs to rolling descents. The technical nature of the course, with its mix of roots, rocks, and varied elevation changes, requires runners to stay present and engaged throughout their effort. The terrain ranges from demanding steep grades that test climbing strength to flowing singletrack sections that reward rhythm and flow. This variety keeps the course interesting across multiple loops while providing different challenges as fatigue sets in during longer distances.

50K

6,063 ft gain

The race follows a looped course through Greensfelder County Park's trail system, showcasing some of the region's most challenging and scenic terrain. Runners navigate more than 80 percent singletrack trails that wind through the foothills of the Ozark Mountains, encountering everything from steep climbs to rolling descents. The technical nature of the course, with its mix of roots, rocks, and varied elevation changes, requires runners to stay present and engaged throughout their effort. The terrain ranges from demanding steep grades that test climbing strength to flowing singletrack sections that reward rhythm and flow. This variety keeps the course interesting across multiple loops while providing different challenges as fatigue sets in during longer distances.

Night 50K

6,063 ft gain

The race follows a looped course through Greensfelder County Park's trail system, showcasing some of the region's most challenging and scenic terrain. Runners navigate more than 80 percent singletrack trails that wind through the foothills of the Ozark Mountains, encountering everything from steep climbs to rolling descents. The technical nature of the course, with its mix of roots, rocks, and varied elevation changes, requires runners to stay present and engaged throughout their effort. The terrain ranges from demanding steep grades that test climbing strength to flowing singletrack sections that reward rhythm and flow. This variety keeps the course interesting across multiple loops while providing different challenges as fatigue sets in during longer distances.

50 Miles

5,896 ft gain

The race follows a looped course through Greensfelder County Park's trail system, showcasing some of the region's most challenging and scenic terrain. Runners navigate more than 80 percent singletrack trails that wind through the foothills of the Ozark Mountains, encountering everything from steep climbs to rolling descents. The technical nature of the course, with its mix of roots, rocks, and varied elevation changes, requires runners to stay present and engaged throughout their effort. The terrain ranges from demanding steep grades that test climbing strength to flowing singletrack sections that reward rhythm and flow. This variety keeps the course interesting across multiple loops while providing different challenges as fatigue sets in during longer distances.

100 Miles

997 ft gain

The race follows a looped course through Greensfelder County Park's trail system, showcasing some of the region's most challenging and scenic terrain. Runners navigate more than 80 percent singletrack trails that wind through the foothills of the Ozark Mountains, encountering everything from steep climbs to rolling descents. The technical nature of the course, with its mix of roots, rocks, and varied elevation changes, requires runners to stay present and engaged throughout their effort. The terrain ranges from demanding steep grades that test climbing strength to flowing singletrack sections that reward rhythm and flow. This variety keeps the course interesting across multiple loops while providing different challenges as fatigue sets in during longer distances.