Police said a southbound vehicle collided with a northbound vehicle when it attempted to pass a semi-tractor-trailer.
The driver of the southbound vehicle, a 70-year-old woman, was declared dead at the scene. Her name was not released by RCMP.
The driver of the northbound vehicle, along with a youth who was a passenger in the southbound vehicle, were taken to hospital in Meadow Lake and then to Saskatoon.
Police said both were reported to have serious but non-life-threatening injuries. There is no word on their current conditions.
Visibility was poor at the time, and police added alcohol is not believed to have been a factor.
RCMP said they continue to investigate.
Green Lake is roughly 300 kilometres northwest of Saskatoon.