Winds forecast to gust near 30 mph Monday could cause problems for crews battling a large wildfire at the Pisgah National Forest in Burke County, authorities say.

Firefighters were pulled back Sunday evening for safety reasons, according to Deborah Walker of the U.S. Forest Service. Walker said crews would return to the lines after a cold front passes, but forecasters say strong winds could continue for several hours after frontal passage.

The blaze is estimated at 2,275 acres, authorities say. As of Sunday, crews had the fire 40 percent contained.

The blaze, known as the Table Rock Fire, started last Monday in the Linville Gorge of northwest Burke County, not far from Table Rock Mountain. It spread rapidly last Wednesday morning, and Walker says about 140 firefighters are battling the blaze.

Authorities say one structure is threatened on private land, and crews are working with the landowner on ways to protect the building.

Crews have set up containment lines around the blaze, although their efforts have been hindered by the steep, rugged terrain in the area. A number of roads and trails are closed in the Linville Gorge area.

Authorities had hoped that enough rain would fall over the weekend to help them contain the fire. But National Weather Service meteorologists say most rainfall amounts were low.

The N.C. Division of Air Quality has issued a Code Orange air quality alert Monday in Alexander, Burke, Caldwell and Catawba counties. That is due to thick smoke, and authorities say smoke also is likely in Watauga County.