A veteran long-distance trail runner from Eagan died during a rigorous race over the weekend on the North Shore, officials said Monday.
Jon Mathson, 41, was participating in the Superior Trail Race late Saturday morning in the 25-kilometer (15.5-mile) event, according to the Cook County Sheriff's Office.
Mathson, a science teacher at Eagan High School since 2007, was between Moose Mountain and Mystery Mountain in Lutsen, a few miles from the finish at Caribou Highlands Lodge, when he collapsed, the sheriff's office said.
Resuscitation efforts by medical personnel, four nurses and an off-duty sheriff's deputy, were performed, but Mathson was declared dead at the scene.
Neither the Sheriff's Office nor race organizers had information on what led to Mathson's death.
Mathson, who had completed the 25K race three times previously, "loved trail running and mountain biking with friends, and was an avid birder," a notice on the race's website read. "Jon ... was revered by his students and co-workers alike."
The extremely hilly and rugged out-and-back course traverses the Sawtooth Mountain Range on the Superior Hiking Trail in the far reaches of northern Minnesota. It runs along Lake Superior and crosses white-water rivers and streams while cutting through forests.
"Our hearts go out to the family of Mr. Mathson, the Superior Spring Trail Race community, and our first responders for this shocking and difficult loss," said Cook County Sheriff Pat Eliasen.