UPDATE (3:30 pm):
Highway 63 has been re-opened at Mariana Lake.
Drivers should still expect delays as traffic is alternating lanes.
Boyle RCMP have shut down Highway 63 at Mariana Lake because of a collision between several vehicles that has left debris on the road.
Witnesses say it looks like a truck carrying lumber hit a truck carrying cars head-on, but there were no serious injuries.
Traffic is being diverted onto Highway 881 until police can clear the road.
Conditions are very poor on roads south of Fort McMurray due to heavy snow.
