The U.S. Coast Guard is warning residents of islands in the river connecting Lake Superior and Lake Huron in northern Michigan that they could be cut off from ferry service during next week's deep freeze.
Those who live on Sugar and Neebish islands in the St. Marys River as well as Drummond Island in Lake Huron are being urged to stock up on supplies including food and heating fuel in case ice blocks ferry service.
Ice-breaking operations are working to keep ferry routes open.
Forecasts for a drop in temperatures came as snow hit the Upper Peninsula, closing Michigan highway 28 in Alger and Marquette counties, as well as parts of the Lower Peninsula.
Dozens of schools were closed Friday in western Michigan and light snow left Detroit-area roads slippery.