Namakan Lake is 16 miles long and 25,130 acres in size, according to the NPS website. (Emily Kurmis / NPS) Rangers, along with U.S. Border Patrol, ...

A park ranger died in the line of duty during a rescue attempt on Namakan Lake in Voyageurs National Park on Sunday, according to St. Louis County Sheriff Gordon Ramsay.

Park officials said the ranger, identified as 55-year-old Kevin Grossheim of Kabetogama, responded to "a call for assistance from a distressed civilian vessel on Namakan Lake" late Sunday morning.