***St. Louis Track Club members will automatically receive a $10 discount (use the same email address that you use for your member registration). Not a member? Click here to join. ***
St. Louis Track Club is excited to invite everyone to join the Corps of Discovery Trail Races, held on the Lewis & Clark Trails in the beautiful Weldon Spring Conservation Area on August 29, 2026.
Course Description:
The half-marathon course covers approximately 13.1 miles and begin from the Lewis & Clark trailhead in the Weldon Spring Conservation Area off Hwy 94 in Defiance, MO. Half marathon participants will first run the 8-mile Lewis Trail and then the 5-mile Clark Trail. The course will travel counter-clockwise and will not be closed to outside use. There will be markings along the course and a volunteer where the trails split.
The 5-mile distance will cover one loop of the Clark trail and the 8-mile option will cover one loop of the Lewis trail. The trail winds itself along the bluffs of the Missouri River down the hardwood-lined ridges and into the hollows so all participants will have something to enjoy.
All distances start at 8:00 a.m.
Half Marathon Course Map
8 mile Course Map
5 mile race Course Map
Sign up before August 15th to guarantee swag! All runners registered before this date will receive swag and a finisher's medal.
Thank you to our sponsor Tailwind Nutrition!
Race Day Details:
CUP FREE: This race is a CUP FREE event. This means that there will be NO paper cups at any of the aid stations. Please carry a water receptacle and fill up as needed with water and/or Tailwind, both of which will be available throughout the course.
PARKING: Parking is in the secondary lot at the Weldon Spring Interpretive Site (7295 RT-94, St. Charles, MO). Please follow the signs and park where guided so as to leave room on the main lot for other trail patrons.
PACKET PICK-UP: All racers can pick up their packets near the parking lot and race start line on race morning starting at 6:30 am.
CUT-OFF TIMES: The cutoff time is 12 p.m., or 4 hours. This is approximately an 18-minute pace per mile. The half marathon course brings runners to the Lewis and Clark trailhead at 8ish miles before heading out to do the final 5-mile loop on Clark. Runners must start their 5-mile loop by 10:30am.
DROP BAGS: We will have a drop bag collection area at the start/finish area. Please mark the bag with your name in case someone has the same one.
RACE START: All distances will start and finish at the Lewis and Clark trailhead. The 5 mile runners will start in quick waves starting at 8 AM and the Half Marathon and 8 milers will start in quick waves at 8:05AM. Since parking is across the roadway at the Weldon Spring site, we will have cones set up to warn drivers and give runners a safe way to be along the roadway. Be sure to pay close attention to the roadway and take caution as you cross.
AID STATIONS: 5 Mile: One manned aid station at mile 3 (water, electrolyte drink, and snacks), plus water and support at the finish line. 8 Mile: An unmanned water-only station around mile 4, and a manned aid station at mile 6.5 (water, electrolyte drink, and snacks). Half Marathon: Runners complete the Lewis loop first, with access to those same stations. They then pass through the start/finish area around mile 8.2 (fully stocked), followed by a final manned station near mile 12 (water, electrolyte drink, and snacks) before returning to the finish.