The blaze ignited in brush Sunday afternoon and still was burning out of control, said Rich Magnussen, a spokesman for the Chelan County Emergency Management office.
Officials hoped rain falling early today would help crews get a handle on the flames in Wenatchee, about 120 miles (193 kilometers) east of Seattle, Washington State Patrol Trooper Darren Wright said.
"We know the fire has grown overnight, and we lost several more structures," Wright said today.
Railroad traffic in the area has been shut down, including freight lines and Amtrak's daily Chicago to Seattle route, BNSF Railway spokesman Gus Melonas said.
Hundreds of firefighters were on the scene and more headed there.