Corps of Discovery Trail Races

AUG
29
2026
Trail races on the Lewis and Clark trails at Weldon Spring Conservation Area offer a Half Marathon, 8 Mile and 5 Mile course with marked routes, aid stations, a four hour cutoff and parking at the Weldon Spring Interpretive Site.
Sat 29 Aug 2026
13 miles 8 miles 5 miles

Always double-check with the organizer's website! This page may contain affiliate links.

Corps of Discovery Trail Races

The Corps of Discovery Trail Races are organized by the St. Louis Track Club and take place at the Lewis and Clark Trailhead in the Weldon Spring Conservation Area near Saint Charles, Missouri. The event uses trails that follow river bluffs, hardwood ridges, and hollows and travels on routes associated with the Lewis and Clark trails.

Distances offered:

  • Half Marathon approximately 13.1 miles, run as the Lewis loop followed by the Clark loop
  • 8 Mile one loop of the Lewis trail
  • 5 Mile one loop of the Clark trail

The half marathon course is run counterclockwise, with the Lewis loop completed before the Clark loop. The course is not closed to other trail users; it will be marked and a volunteer will be stationed at the trail split. Aid station coverage varies by distance and is positioned roughly at the mile points listed by the organizer: the 5 Mile course has a manned station near mile 3 plus support at the finish; the 8 Mile course includes an unmanned water station and a manned station near mile 6.5; the half marathon accesses those stations and additional stocked stations later in the course.

The event is operated as a cup free event, so no paper cups will be available at aid stations. Water and electrolyte drink will be available on course. Parking is directed to the secondary lot at the Weldon Spring Interpretive Site at 7295 RT 94, St. Charles, MO. Packet pick up is available near the parking area and the start finish area on race morning. A four hour cutoff applies to the course. Visit the organization's website for the most recent information.

13 mi
Half Marathon
8 mi
8 Mile Lewis Trail
5 mi
5 Mile Clark Trail