The Carlton Complex of fires covers 28 square miles of the valley near the town of Twisp, and is being pushed by high temperatures and strong winds.
Fire spokesman Jacob McCann also said there have been unconfirmed reports that eight other homes have burned in the four blazes that make up the complex and noted that "we have extreme fire behavior and rapid growth."
The fires have prompted the closure of Highway 20 at Loup Loup Pass, he said.
Meanwhile, another wildfire about 100 miles south chased people from nearly 900 homes as it burned near the Bavarian-themed village of Leavenworth.
The Chiwaukum Creek Fire sent a light dusting of ash over Leavenworth, where the German-style motif provides a backdrop to Oktoberfest and a Christmas tree lighting festival.
The fire's smoke plume rose 25,000 feet into the air. The blaze closed 35 miles of U.S. Highway 2, stretching from Leavenworth to Stevens Pass in the Cascade Mountains.
"There's a huge cloud of smoke above us," Don Hurst, a retired firefighter who lives just outside of Leavenworth, said Thursday morning. "The winds started to pick up a little. It's just like snowfall here with the ash coming down. It's fine ash. We're getting all this ash fall."
Residents of 860 homes have been told they should leave immediately, fire officials said. Another 800 homes were less seriously threatened.
Authorities said Thursday morning that the Chiwaukum Creek Fire has grown to more than 10 square miles. It was first detected Tuesday.
"The weather and winds are not in our favor," said fire spokeswoman Mary Bean. She said temperatures were expected to top 100 degrees with winds gusting to 30 mph in the area Thursday.
She said the cause of the fire is under investigation.
About 1,000 firefighters were fighting blazes around the state that included the Mills Canyon Fire, the state's largest at 35 square miles.
Worsening wildfire activity has prompted the governor's offices in both Washington and Oregon to declare states of emergency, a move that allows state officials to call up the National Guard.