DULUTH — The Spice Lake Fire that began Tuesday in the Boundary Waters Canoe Area Wilderness was still smoldering Thursday night as forest officials closed a large area of the wilderness surrounding it.

A closure order for the area, effective Friday, prohibits visitors on approximately 100,000 acres of trails, portages, rivers and lakes surrounding the fire, including a portion of the Kekekabic Trail. It affects 80 campsites.

Popular entry points affected include Moose Lake, Saganaga Lake, Seagull Lake and Snowbank. The U.S. Forest Service said it notified affected permit holders and outfitters.

The closure comes, in part, because the area is highly remote, according to the Superior National Forest. "It takes an extended length of time to paddle the area, the capacity for extreme fire behavior and excessive fuel conditions all lend to a large fire growth potential," the service said in an online post. "These factors combined require a large closure area until we have complete containment."

A 19-person hotshot crew is expected to arrive within the next few days to work the 20-acre fire from the ground, the Forest Service said. The elite team was ordered because of the logistics of supporting firefighters in such a remote area.

The Forest Service had been paddling into the area to disperse backcountry visitors near the fire. Campfire restrictions in the Superior National Forest, which includes the Boundary Waters, were already announced.

Firefighters were flown to the area by float planes, and aerial water drops continue to be conducted.

"These are not normal circumstances, the drought, warm temperatures, unpredictable high winds and fuel loads are creating a dangerous condition for our firefighters and the recreating public," the post said.

The Spice Lake fire was discovered Tuesday afternoon on a routine wildfire detection flight, only hours after the Superior National Forest announced a campfire ban for the entire BWCA.

The area of the fire includes dead downed and standing trees that were killed by spruce budworms, the Forest Service said.