The fire is now burning near Hook Lake, 10 kilometres east of Labrador City and Wabush.
Winds are blowing it towards Moosehead Lake, where it started Sunday afternoon.
The blaze forced the evacuation of cabins east of Labrador City and Wabush.
Five cabins were destroyed. There have been no injuries reported.
Conservation officer Chuck Porter says two water bombers are working to attack the fire.
Heavy smoke Sunday led the Royal Newfoundland Constabulary to close a section of the Trans-Labrador Highway.
Insp. Paula Walsh says police have set up a checkpoint to keep other drivers off the road.
“No new traffic will be permitted to enter onto the Trans-Labrador Highway today until a further update is provided to the Royal Newfoundland Constabulary from the Department of Natural Resources as they assess the fire conditions,” Walsh said.
In a statement issued around 9:30 a.m. Monday, the RNC indicated that commercial vehicles containing necessary supplies, individuals with medical concerns and those with legitimate business will be escorted through affected areas.
But those escorts have now stopped, as smoke clouds roll above trees just off the Trans-Labrador Highway.
Crews say thick smoke is hovering around the highway inside the road block.
Officials are worried the blaze may jump back over the highway.
Porter is asking people in western Labrador not to start campfires, noting that conditions are ripe for additional forest fires.