Course
Held at Maramec Springs Park near St James, with 5K, 10K, 20K, 50K, 50-mile, 100K and 100-mile options on the main Saturday and a longer-cutoff 100-miler starting the week before.
100 Mile100 mi
100K100 km
50 Mile50 mi
50K50 km
Key dates
- !RegistrationOpen now
- ★Race daySat 13 Feb 2027
Date confirmed with the organiser · entry window checked by RunCalendar
About
Iron Heart is a trail ultramarathon held near St. James, Missouri each February, in the Ozark backcountry. Runners choose from 50K, 50-mile, 100K, or 100-mile distances, testing endurance through rolling Ozark terrain in the depths of winter.
Your next race, seen from above.
Save Iron Heart to your season and RunCalendar reminds you the morning entries open and before they close. Free on iPhone, no account needed.
Get RunCalendar
Save Iron Heart to your season and RunCalendar reminds you the morning entries open and before they close. Free on iPhone, no account needed.
More races in Missouri All ›
-
Running From Yeti St. Louis, MO
Novelty run chasing a costumed Yeti mascot
-
The FROZEN STICK 5 Mile and Half Marathon Trail Run
Runs the Bluffview, Rock Hollow and Zombie Trails
-
Runnin' Against Multiple Sclerosis 5k
Starts at Mizzou's Tiger Plaza in Columbia
-
Run this event? Claim it on runcalendar.com
Visit event website ›
A confirmed date shows its day; a provisional one shows only its month, because we won't claim a day we don't have. This page is rebuilt every night from the RunCalendar catalogue.