A 45-year-old Perham man was driving a pickup on Little Pine Lake Friday night before dense fog led him to sink it in open water.

Craig Swanson was using a GPS unit to navigate on the ice, but because of dense fog, he did not  see open water where the Otter Tail River flows into the lake.

The vehicle sank in more than 10 feet of water.  Swanson got out and swam to the ice.  He lost his boots, and had to walk a half-mile to his home in only his socks. 

Swanson suffered mild hypothermia, but refused medical attention.