SPRINGERVILLE, AZ - (CNN) -The progress that firefighters in Arizona made over the past two days against a giant wildfire were expected to be tested Saturday by high winds that could stoke the flames.
Firefighters had put their efforts in creating "lines" to contain the fire. To keep the fire from spreading, they burned off areas to destroy ground fuel that feed the large fire.
"Today is the day that the good work we did over the last two days gets challenged," U.S. Forest Service spokeswoman Suzanne Florey told CNN.
As of Saturday morning, the fire was 6% contained.
Separate teams were tackling the fire in three different areas, Florey said. The Wallow Fire has scorched more than 408,876 acres, leaving a giant bear-paw-like burn mark on the map of eastern Arizona.
Wind gusts of up to 30 miles per hour were possible in some areas of the massive fire, forecasters said.
The winds mean that firefighters will be focusing on making sure existing lines work, Florey said. There is also the risk of embers being blown for miles past the control lines, causing spot fires, she said.
A priority on Saturday will be safety and protection of structures, she said.
The flames have consumed 29 homes, 22 of them in the evacuated city of Greer. More than 5,200 homes are threatened, according to officials.
"The weather conditions will be going back to less favorable conditions," said John Helmich, spokesman for the Southwest Interagency Incident Management team.
On Friday, air and ground crews concentrated on protecting residences and structures in and near the evacuated cities of Springerville and Eagar.
More than 3,000 people are working to douse the fire, from the ground and air. About 221 fire engines and 14 helicopters were in use.
Power companies said Friday that they are still watching the huge fire and its potential impact on crucial transmission lines that supply power to hundreds of thousands.
El Paso Electric said the fire is about 15 miles from lines that serve nearly 400,000 people.
The utility is working with partners and other companies on other sources of power if the lines are closed, company spokeswoman Teresa Souza told CNN. If that occurs, customers in southeastern New Mexico and El Paso, Texas, could see rolling blackouts.
Tucson Electric Power has two lines about 8 miles from the fire. Those lines carry electricity through the region to Tucson.
"We're watching it carefully," spokesman Joe Salkowski said.
If the lines are closed or damaged, the company will be able to prevent outages by using other power sources, Salkowski said.
Tucson Electric Power has a coal-powered plant about 12 miles northeast of Springerville, which is evacuated. Officials are safeguarding the plant, but its distance from the fire and the grassy terrain make it "reasonably protected," the spokesman said.