Beauval RCMP say four people were injured when the driver of a truck lost control and rolled into a ditch on Highway 965 on Sunday afternoon.
The truck was travelling west on the highway at the time of the accident between Canoe Lake and Cole Bay.
Police say three of the four occupants were ejected from the vehicle with the other trapped inside.
The 47-year-old male driver was taken to hospital in Ile-a-la-Crosse and later taken to Saskatoon hospital by air ambulance.
A 30-year-old female, 52-year-old female and 50-year-old male were also taken to Saskatoon hospital.
The 50-year-old male has since been released.