Iron Heart

FEB
13
2026
Celebrate Valentine’s Day on the trails at Maramec Spring Park with Iron Heart, offering distances from 5K to 100 miles. Scenic singletrack, hot quesadillas at aid stations, and finisher awards make for a memorable winter run.
Fri 13 Feb 2026
100 miles 100 kilometers 50 miles 50 kilometers 20 miles 15 miles 20 kilometers 10 miles 15 kilometers 10 kilometers 5 miles 5 kilometers

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Iron Heart at Maramec Spring Park, St. James, MO

The Iron Heart is a February trail running event held at Maramec Spring Park, with the Massey Hill Shelter as the central location. The event is presented as a Valentine’s Day trail run and includes solo, relay, and ultra-distance options. Packet pickup and a pre-race pasta meal are organized the day before at the Massey Hill Shelter (RSVP requested). Timing services are provided by Split Second Timing.

Distances and course

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

The course uses two named trails: Leatherbritches Trail (1.8 miles) and BallHooter Trail (3.2 miles). BallHooter is noted to have about 246 ft of elevation gain. An aid station stands at the changeover between the two trails and stocks electrolyte drink, water, and hot quesadillas.

Rules, awards, and logistics

Pacers are allowed for the 100 Mile (after mile 50) and 100K (starting at mile 52); pacers must check in and pick up a pacer bib. No pacers, including cyclists, are permitted for other distances. Cutoff and finish policies include a standard 32-hour cutoff and an early-start option that extends the 100 Mile cutoff to 36 hours; early starters are not eligible for overall male or female awards. Overall male and female awards are given for all distances; custom belt buckles are awarded to finishers of the 100 Mile, 100K, 50 Mile, and 50K, and custom gym bags are provided to 100 Mile finishers. Camping is allowed, including parking lot camping without hookups; the park also lists campsite options and two platform glamping sites. Spectators and well-behaved pets are permitted. Visit the organization's website for the most recent information.

100 mi
100 Mile
100 km
100 Kilometer
50 mi
50 Mile
50 km
50 Kilometer
20 mi
20 Mile
15 mi
15 Mile
20 km
20 Kilometer
10 mi
10 Mile
15 km
15 Kilometer
10 km
10 Kilometer
5 mi
5 Mile
5 km
5 Kilometer