Show Low, Ariz. ? A fire in the tinder-dry forests of eastern Arizona raced through a hastily abandoned town Thursday, chasing firefighters off the line and prompting the evacuation of thousands of residents as it quickly grew to 85,000 acres.

“This is a monster,” said Jim Paxon, a U.S. Forest Service fire information officer.

A fire warning sign states the obvious as smoke from the Rodeo fire billows high above Linden, Ariz. The monster wildfire on Thursday roared across 85,000 acres of forest in eastern Arizona and began burning structures on the outskirts of a deserted community, officials said.

The fire roared through the upscale vacation community of Pinedale. Fire information officer Jim Anderson said “more than a few” homes had burned, but he said officials probably won’t be able to start assessing the damage until early today.

Virtually all 390 residents had fled a day earlier and fire crews had to pull back because the fire was too dangerous. Officials estimated the flames were reaching 2,000 degrees.

“We’re at the mercy of Mother Nature right now. There’s not a whole lot we can do with it,” said Larry Humphrey, a fire commander.

The so-called Rodeo fire began Tuesday about 110 miles northeast of Phoenix and it was nowhere close to being contained. It has forced more than 4,000 people to flee their homes in Pinedale, Linden and Clay Springs.

Another blaze burning across 2,600 acres of the Fort Apache Indian Reservation forced the evacuation Thursday night of about 4,000 residents in the communities of Heber-Overgaard and Aripine, said fire spokeswoman Chadeen Palmer. That blaze began as a signal fire started by a lost hiker.

“It’s just a waiting game,” said Bob Jackson, who along with his wife fled to an evacuation center. “All you can do is say a prayer.”

Residents of Show Low, a city of 7,700 just east of Pinedale, and another 3,500 people in neighboring Pinetop-Lakeside were told to be ready to evacuate on an hour’s notice.