Kootenai County authorities said a man fell asleep behind the wheel and drove into the Coeur d'Alene River near Cataldo.
The sheriff's department said it is investigating the crash that happened early Monday on South CCC Road.
A statement from the department said 27-year-old Jesse Story was driving along the road in his pickup truck when he fell asleep. The truck hit a tree, rolled over and ended up submerged in the river.
Story freed himself and swam to shore. He was treated at Kootenai Medical Center for non-life-threatening injuries.
The sheriff's department said alcohol is not believed to be a factor in the crash.