ANCHORAGE, Alaska -- An Alaska wildfire grew to 15,000 acres and officials warned travelers on the main highway between Anchorage and Fairbanks to expect delays of two to three hours Friday because of the blaze.

The Tamarack Fire was burning along the Parks Highway near Nenana, about 55 miles southwest of Fairbanks. The highway was being closed intermittently because of smoke and to avoid interference with firefighting equipment.

Nearly 300 firefighters were on the fire, which had burned an area about 10 miles long and a mile wide.

Jennifer Yuhas, a spokeswoman for the state Division of Forestry, said one home four miles from Nenana had been destroyed. Golden Valley Electric Association turned power off along the Parks Highway to minimize the hazard of live wires, she said.

The fire began Wednesday at a home along the highway when embers from a burn barrel ignited grass or brush. Strong wind pushed flames into wooded areas and toward Nenana, an Interior Alaska river and rail transportation hub of about 550 people.

The fire closed to within a mile of the town, but the Tanana River and the Nenana airport stood between it and the flames. Smoke presented a breathing hazard for people with respiratory problems, according to the Alaska Department of Environmental Conservation.

Fire information officer Pete Buist said changes in wind direction caused firefighters headaches Thursday. Wind that blew the fire north toward Nenana switched and sent fire racing in other directions, including south down the highway corridor.

Buist said most of the firefighters on the ground are concentrating on structure protection and were using chain saws to clear the area in front of the fire near the airport.

The state Forestry Division also is fighting the fire from the air with a fixed-wing command aircraft and four air tankers.