The Washington State Department of Natural Resources says about 200 firefighters are battling the Red Apple Fire.
The fire was threatening homes, apple orchards, and an electrical substation, but no structures have been lost.
Chelan County sheriff’s deputies executed a search warrant at a home Wednesday believed to be connected to the start of the wildfire.
The cause remains under investigation.
The fire started Tuesday evening and is burning grass and sage near US Highway 2.
Residents of more than 1,500 homes were under evacuation notifications.