An avid outdoorsman and well-known recreation director died Sunday after being struck by a vehicle while bicycling in Detroit Lakes.

Mark Knutson, 53, was hit by a pickup towing a boat just after 7 a.m. while he was biking westbound on South Shore Drive in Detroit Lakes, according to Detroit Lakes Police Chief Steve Todd.

Knutson, who was general manager of Detroit Mountain Recreation Area in Detroit Lakes and director of the Fargo Marathon, was flown by helicopter to Sanford Hospital in Fargo, where he died. Todd identified the driver as a 42-year-old man from Fargo. No criminal charges have been filed but the investigation is ongoing.

Todd said Knutson had recently moved to Detroit Lakes, where he ran the popular resort that offers skiing and snowboarding in the winter and biking in the summer.

"He was a really talented guy and full of energy and just getting his feet under him here in Detroit Lakes," Todd said. "He would have made a huge difference just with promoting the city, and health and fitness.

"It's such a tragedy," Todd added. "He was a friend of mine. It's just been a difficult couple of days."

The news hit the bicycling and running world hard. Race director Mary Anderson said she started to receive texts about a possible accident involving Knutson. She was hoping it wasn't true.

"It's just horrible," Anderson said Monday. "We are good friends. I can't even process it yet."

Through her company Anderson Race Management, she puts on dozens of races throughout the state each year. Anderson had worked with Knutson on the Fargo Marathon, which includes a week of events leading up to race day.

"He had the energy and wherewithal to do all the things that had to be done," Anderson said.

Organizations that worked with Knutson also filled Facebook with tributes.

"Mark was a visionary and we were excited about his involvement and future events and ideas he had for Detroit Mountain," read a post from the Detroit Mountain Recreation Area.

The Essentia Health-Fargo Marathon page stated the void left by Knutson's untimely passing is "immeasurable."

"Mark, simply put, was not just the race director of the Fargo Marathon, but its very essence. His warm and genuine nature endeared him to all who had the privilege of meeting him during his races, and his kindness, drive, and passion were evident to everyone he encountered," the post states. "His absence will be deeply felt by the entire Fargo community and the running world at large. We will miss him dearly."

Project 412, a nonprofit community-building group, stated it has lost a dear friend.

"Knutson helped us get started and was our second employee for a blink of time until the opportunity to manage Detroit Mountain Recreation Area, Inc., came along, which is where [Detroit Lakes] needed him to be. Mark was so special and he was 'all in on DL,'" the post states.

Knutson's Facebook profile states he grew up in Hillsboro, N.D., and studied business finance at Minnesota State University Moorhead. He was a father and grandfather. Funeral details have not yet been posted.

Staff writer Bob Timmons contributed to this report.