ST. GEORGE — High winds, low humidity and soaring temperatures continue to hamper efforts of more than 400 firefighters battling a growing wildfire less than 10 miles from here.

"The fire is burning on the west side in really steep terrain," said David Boyd, fire information officer with the Bureau of Land Management.

The fire has now burned 28,500 acres of dry grasses and shrub, said Jodi Hamel, a BLM fire information officer. The fire, which began Saturday, has grown quickly from 6,600 acres.

Numerous communication towers are in the potential path of the Apex fire, said Boyd.

"The towers are maybe a mile away (from the advancing fire) on West Mountain," said Boyd. "It's very difficult to get firefighters in safely, so we're putting a lot of fire retardant down. That's a priority for us."

Two 16-year-old boys playing with matches are suspected of starting the fire on private property near the OMB Apex mine, said Washington County Sheriff Kirk Smith.

The communities of Kayenta, Gunlock and Motoqua are in no danger, said Boyd, although evacuation plans are laid out in case of an emergency. Several families living on the Shivwitts Indian Reservation south of Gunlock were evacuated as a precaution Sunday evening, but all had returned to their homes by Monday morning.

On Tuesday afternoon, the American Red Cross Greater Salt Lake Area Chapter announced it was sheltering 25 residents from the reservation and had mobilized a trailer stocked with supplies that could take care of up to 100 people. Local volunteers are on alert should neighboring areas have to be evacuated.

Fears that the fire would destroy power poles and damage wells near Gunlock reservoir were laid to rest Tuesday. Up to 20 percent of the culinary water used by St. George residents is pumped from Gunlock.

"For a little while it looked like the fire was moving toward the Gunlock wells, but the firelines seem to be holding," said Barry Barnum, St. George director of water and waste water. "Our power lines are being protected, and our residents are doing just great in conserving water."

Washington County residents will see smoke and haze in the sky for some time to come, Boyd said.

"There are some isolated smoke pockets, but those fires are contained. It's just back burning," he said. "We don't know yet when the rest of the fire will be contained."

Four single-engine air tankers, three heavy air tankers, two air attack crews, one medium helicopter and three smaller helicopters are also being used.