By Mike Saucier
PHOENIX (Reuters) - An Arizona wildfire threatened two more towns on Friday, with high winds on the way, as firefighters made progress against the largest of several fires spreading across the U.S. Southwest.
More than 1,000 firefighters in Arizona and Colorado were battling five major blazes that have consumed more than 55 square miles (142 square km) of ponderosa forest, brush and grass, and a new blaze erupted in Utah on Thursday.
The Gladiator Fire in central Arizona, which has already destroyed four structures and forced the evacuation of about 350 residents of the old mining town of Crown King earlier in the week, was threatening two more tiny communities.
U.S. Forest Service spokeswoman Debbie Maneely said that residents of Battle Flat and Pine Flat, which have fewer than 50 homes combined, have been alerted to evacuate within 24 hours.
Maneely said the situation was "really critical," with 40-50 mph winds predicted, and that more crews and equipment were being called in to fight the blaze, which has burned about 15 square miles in the Prescott National Forest since it erupted on private property on May 13.
Meanwhile, crews made slow progress against the biggest of four fires in Arizona, which has scorched 22.6 square miles in the Tonto National Forest, about 40 miles north of Phoenix, since it started on May 12.
The Sunflower Fire was 15 percent contained on Friday, up from 10 percent a day earlier, Fire information officer Rick Hartigan of the Arizona Central West Zone Incident Management team said.
In Colorado, a wind-driven wildfire grew to 12 square miles overnight, as some 500 firefighters struggled against the blaze in low humidity, hot temperatures and rugged terrain, fire officials said.
The human-caused Hewlett Fire has burned for five days in the Roosevelt National Forest, incident spokesman Greg Heule told reporters on Friday.
No structures have been lost but residents of 15 homes were under a mandatory evacuation order, he said.
Governor John Hickenlooper declared the fire a disaster emergency on Friday, activating the Colorado National Guard and freeing up $3 million to assist in fire suppression efforts.
In Utah about 100 firefighters were battling the 500-acre (202-hectare) 73 Fire, which began on a state road about 60 miles southwest of Salt Lake City.
By mid-day, the blaze was about 50 percent contained, with light rain and cool temperatures aiding firefighters, although expected high winds for the afternoon could pose a threat. No homes or structures have been threatened.
(Additional reporting by Keith Coffman and Jennifer Dobner; Writing by Mike Saucier and Cynthia Johnston; Editing by Xavier Briand)