One person died after a Tuesday morning crash between a car and a semi-trailer on Highway 63, 30 kilometres north of Mariana Lake.
The car's passenger died in the collision, and the driver suffered serious injuries.
The truck's driver was not hurt.
The collision occurred around 10 a.m. and police closed the highway to conduct their investigation.
The southbound lane of Highway 63 was opened by midday, and RCMP were planning to alternate southbound and northbound traffic through that single lane.
However, police would prefer that people stay off the road.
Conditions on Highway 63 are extremely poor and travel is not recommended, RCMP said.
Mariana Lake is approximately 100 kilometres south of Fort McMurray.