Chris Hasbrouck, of Pittsboro, died Wednesday at the University of Tennessee Hospital in Knoxville.
Hasbrouck had volunteered with others from his ROTC program to run the Mountain Men Memorial March in Gatlinburg on April 21. He collapsed on mile 10.
It appeared Hasbrouck suffered a heat-related illness.
However, temperatures were in the 60s the day of the race, and Hasbrouck was seen drinking water before the march.
What exactly caused his death may remain a mystery.