There's been a dramatic increase overnight in the burned acreage numbers on the Wallow fire 12 miles southwest of Alpine in eastern Arizona.

U.S. Forest Service spokeswoman Jonetta Trued tells The Associated Press the wildfire has increased to more than 40,500 acres with zero containment.

Trued says the wildfire is burning dead trees and branches lying on the forest floor. When an ember hits, there's 100 percent ignition which leads to spot fires and hazardous conditions for fire crews.

Fire authorities say the winds are strong, temperatures are up and humidity is low making it a critical fire event.

Trued says crews are watering down areas near a historic lodge to protect it from the wildfire burning to the west.

Structure protection crews are also in place at the Beaver Head area south of Alpine where there are a number of homes.

Dyson says residents have been evacuated from those areas.

Meanwhile, Highway 191 is closed from Alpine to Hannagan Meadow as a precaution as fire trucks roll up and down the highway.

ABC15's Katie Raml, Eric English and Jennifer Parks are on their way to the fire. Check back for updates throughout the day on and tonight on ABC15 News.