The Backbone Fire, which has prompted evacuation orders for communities northwest of Payson, continued spreading overnight, authorities said Monday morning.
The blaze expanded to 32,757 acres with zero containment, according to the latest incident command update, up from 24,198 acres reported Sunday night.
Crews on the eastern edge of the fire are working to protect the communities of Strawberry and Pine, which remain under evacuation orders. Firefighters on the western front are battling to keep the flames from jumping the Verde River.
More than 340 personnel have been assigned to fight the Backbone Fire, which was ignited by lightning 12 miles west of Strawberry on June 16.
In addition to the evacuations, the fire has prompted the closure of the Fossil Creek Recreation area.
An evacuation shelter was opened at the Rim Country Middle School at 304 S. Meadow St. in Payson. Livestock can be sheltered at the Payson Event Center, 1400 S. Beeline Highway.
State Route 260 has been closed in both directions between Camp Verde and SR 87, and SR 87 is shut down from Payson to Lake Mary Road.