A pre-evacuation notice is in effect for Essex and the surrounding area as increased activity on the Sheep Fire — burning about 2 miles due south of the community — was expected to pick up significantly Wednesday night and today.

“It’s not real close, but the behavior analysts are predicting it’s going to move substantially overnight and tomorrow,” Flathead County Undersheriff Dave Leib said Wednesday. “Fire conditions are not bad at this point in time, but tomorrow there’s a red flag warning with low humidity and high winds.”

Leib and other local officials headed to the area on the southern edge of Glacier National Park to warn affected residents of the notice. About 90 structures are considered threatened, including  50 residences, 20 businesses and 20 additional buildings.

Greg Dinetto, a spokesman for the Thompson-Divide Complex fire team handling the Sheep Fire, said all firefighters had been taken off the fire Wednesday afternoon due to unsafe conditions.

“In the last couple hours we’re experiencing increased winds, and it’s a little warmer and a little drier so the fire has expanded,” he said.

“This is not catching us unaware. It’s something that we’ve been planning and expecting, so we have done everything we can with the resources we have available. ... This wind is obviously not affecting just us, so we’re all trying to get the same resources and they’re just not there.”

He added that the fire was working downslope toward U.S. 2. The fire had covered 93 acres as of Wednesday night.

Single-engine tankers dropped retardant and helicopters made frequent water drops on the fire on Wednesday.

The fire was 1.5 miles from the highway by early evening Wednesday, and he said the fire team was concerned about the possibility of a wind event pushing the flames over the highway and the Middle Fork Flathead River and into Glacier National Park.

Park officials have begun structure protection on Walton Ranger Station complex buildings across the river from Essex, and rangers had begun sweeping trails and backcountry campgrounds to clear out hikers and campers in the area.

The fire information hotline for the Thompson-Divide Complex is (406) 314-1669.

Reporter Samuel Wilson can be reached at 758-4407 or by email at swilson@dailyinterlake.com.