MUNISING, Mich —  Authorities say they rescued a family of four from Minneapolis that got stranded while canoeing in Lake Superior along Pictured Rocks National Lakeshore in northern Michigan.

The Alger County sheriff's office says a tour boat operator reported several people were stranded along the Upper Peninsula lakeshore about 9 p.m. Tuesday. Rescue boats were sent.

Two adults were canoeing with two young children along the shore when they were overtaken by winds and waves. They ended up swimming about 150 yards to shore to reach a beach, where they were eventually spotted by passengers and the captain of the tour boat. 

Captain David Sliter of Pictured Rocks Cruises tells KARE 11 he was piloting a sunset cruise around 8:45 p.m. and had just navigated a storm with rain and high winds when he saw a flash of yellow at the bottom of the bluffs, something that shouldn't have been there. It turns out it was a life jacket.

"I stopped, looked and saw four people there. So I'm trying to decide what's going on and I saw two adults and two kids," Sliter recalled. "I decided they were in trouble."

Sliter's boat is big enough it could not navigate the shallows to pick the stranded family up, so he radioed the sheriff's department and rescue boats were dispatched. The tour boat kept an eye on the stranded canoeists until first responders arrived. 

"They were slumped over, looking like they were cold and wet," the captain recalled. "They had just swam 150 yards in 47 degree water, so they were fighting hypothermia at that time."

The family was rescued and taken to a hospital for evaluation. Names of the Twin Cities residents weren't immediately released. Sheriff's officials are urging people to use "extreme caution" when venturing out on Lake Superior.