Iron Heart

Saint James, United States • 13 Feb 2026

Event overview

The Iron Heart event takes place in mid-February 2025 at Maramec Spring Park, Massey Hill Shelter, 21880 Maramec Spring Dr, St. James, Missouri. It is a trail running event held around Valentine’s Day and includes options for solo runners and relay teams. Split Second Timing will provide on-site timing and results. Awards include overall male and female awards for all distances, with custom belt buckles for finishers of the longest distances and custom gym bags for 100-mile finishers. Packet pickup and a pre-race pasta meal are scheduled the day before the main event.

Course, distances and logistics

The course uses trails in Maramec Spring Park, including Leatherbritches Trail (about 1.8 miles) and BallHooter Trail (about 3.2 miles with roughly 246 ft of elevation gain). An aid station is located at the changeover between the two trails and will offer electrolyte drink, water, and hot quesadillas. Pacers are allowed for the 100-mile and 100K distances under specified conditions; no pacers are permitted for other distances. Standard cutoff for the event is 32 hours; an extended 36-hour cutoff is available for 100-mile runners using an early start option. Camping is allowed in the parking lot (no hookups); Maramec Spring Park also lists campground site types and nightly fees. Distances offered include: Visit the organization's website for the most recent information.

  • 100 Mile
  • 100K
  • 50 Mile
  • 50K
  • 20 Mile
  • 15 Mile
  • 20K
  • 15K
  • 10 Mile
  • 10K
  • 5 Mile
  • 5K

Race information

100 mi
100m
100 km
100k
50 mi
50m
50 km
50k
20 mi
20m
15 mi
15m
20 km
20k
10 mi
10m
15 km
15k
10 km
10k
5 mi
5 km
Visit the organization's website for the most recent information.
Trail runs nearby

Test your grit at the Lion King Backyard Ultra in Rolla, Missouri on October 10, 2026. Runners complete repeated 4.167 mile loops each hour until one athlete completes one more loop than all others.