Two lightning- caused wildfires spread on Thursday to more than 650 acres north of Carefree and Scottsdale in the Tonto National Forest.
Almost 150 firefighters are expected to be battling the Humboldt and Lookout fires again today, said U.S. Forest Service spokeswoman Emily Garber.
"We have no estimate yet of when we’ll be able to contain them,’’ she said.
The fires that started about a mile apart on Wednesday were burning into each other by Thursday morning several miles from the northeast edge of Scottsdale.
Fire crews were managing to keep flames away from a Federal Aviation Administration air-traffic communications station on Humboldt Mountain and large power lines that feed into the Valley, Garber said.
Two FAA employees were evacuated from the station shortly after the Humboldt fire broke out, she said. The FAA’s operations have not been interrupted.
A Forest Service employee also was evacuated from a fire lookout tower.
On Thursday, firefighters moved into the nearby Red Rover Mine area to protect several residential trailers and other structures, Garber said.
The fires are not threatening the popular Seven Springs campground, which is about four miles away.
The two blazes are the latest in a rash of wildfires on the outskirts of the north East Valley this summer.
Drought has left large swaths of dry desert vegetation while monsoon-season storms have brought a lot of lightning but little rain.
There have been about a dozen lightning-caused fires in the area during the past six weeks, said Forest Service spokesman Dave Killebrew.
"There could even be some small ones smoldering out there right now that we don’t know about yet,’’ he said.
Two of the larger ones burned for a week before being extinguished on Aug. 7. The Jack fire charred 280 acres north of Scottsdale and Carefree. The Lewis fire burned about 150 acres just north of Cave Creek.