Firefighters continue to battle a big wildfire that’s closed Highway 97 between Toppenish and Goldendale. Washington Transportation Department officials say the wildfire is burning on both sides of U.S. Highway 97.

Officials from the Department of Natural Resources say flames and smoke were causing hazardous driving conditions so they closed the highway Wednesday afternoon. The fire was first reported Wednesday morning and had burned across about 1,200 acres, or nearly 2 square miles, by that night.

Forty firefighters and two water-dropping helicopters fought the fire, which sent up a huge column of white smoke over the lower valley yesterday and last night.

More firefighters are expected on the scene today. The wildfire is burning in forest and grassland on the Yakama reservation north of the summit of Satus Pass.

The cause is under investigation.