Voyageurs National Park has begun removing navigational markers and buoys from waters within its boundaries.
Park staff have started their work on Rainy Lake this week.
They will then move to other area lakes in the coming days, depending on the weather.
The park also reminds visitors that hunting and trapping is prohibited on federal lands and all waters within the boundary of Voyageurs National Park.
This includes the removal of animals that enter the park after being shot outside its boundaries.
If a wounded animal enters the park, licensed hunters must contact a law enforcement ranger for assistance in tracking and removing the animal.
The phone number to call is (440) 546-5945.