The Gold Pan Fire Complex currently burning in wilderness areas about 35 miles southwest of Darby was very active on Tuesday, growing by almost 2,000 acres to over 13,000 acres.

Fire Information Officer Bob MacGregor said an effort was underway to protect historic structures in the area.

"We're trying to protect the historic MacGruder Station up there, which is an old Forest Service ranger tower and associated outbuildings from the 1920's," MacGregor said. "We've also wrapped protective foil around the Hell's Half-Acre Lookout."

MacGregor said the fire's rapid growth is of great concern to fire officials, due to the fact that the actual fire season is really just getting started.

"Its very early in the season, and so the Bitterroot National Forest officials are quite worried about this fire, because it got started so early and there's still a lot of fire season left.

Officials say a Type 1 team, the most experienced type of organization, will be taking over command of the fire complex on Wednesday morning. The fire has been burning since it was started by lightning on July 16.