Thick smoke from the massive Mustang Complex fire forced officials to close a section of Highway 93 near the Montana - Idaho state line Thursday night and Friday morning.

Traffic there had to be guided by a pilot car until visibility improved. Officials said travel in the area will be difficult even when the smoke clears.

"It's kind of a trade off. Without fire, driving and the smoke issues are much better during the day, but there's always potential during daylight hours for more fire activity to increase," said Public Information Officer Pete Gordon.

Gordon said crews continued burnouts along the highway corridor Friday to keep the spreading fire in check.

To date it’s burned almost 300,000 acres.

Evacuations are still in effect along a 13-mile stretch of Highway 93, between Quartz Creek and North Fork, Idaho.

The fire grew about 900 acres in Montana’s Johnson Creek area, and officials expect the fire to pick up speed with upcoming weather.