ISABELLA  — Calmer winds, cooler temperatures and a few moments of sleet and light snow brought encouragement Wednesday as firefighters continued efforts to contain a blaze that was in a “pause mode” — days after it moved at breakneck speeds, swallowing nearly 160 square miles of forest along the Minnesota-Canada border.

The fire in the Boundary Waters Canoe Area Wilderness is one of the largest on record in the state, and just under half of the access points into the wilderness were closed to campers by midday Wednesday. Less than 50 buildings — including cabins — had been evacuated.

Plumes of smoke from the fire drifted into Michigan, Wisconsin and northern Illinois on Tuesday, but the plume had largely dissipated by Wednesday because of the drop in heat and wind, and it was less visible because of overcast skies, said Mary Shedd, a Forest Service spokeswoman in Isabella.

What remained of the plume was expected to continue to move southeast. Officials in southern Wisconsin said the air quality in that part of the state would be unhealthy for everyone until late Wednesday.

The fire, which started with a lightning strike Aug. 18, took off quickly earlier in the week, as 30 mph wind gusts ahead of a cold front caused it to spread east. Kris Reichenbach, a spokeswoman for the Superior National Forest, said the fire had “unprecedented growth.”

But by Wednesday, officials were catching their breath.

“Right now it is in a pause mode,” Jim Grant, from the U.S. Forest Service, said of the fire. He told roughly 100 residents gathered at the Isabella Community Center that officials did not expect the fire to move much on Wednesday.

Grant said about 300 firefighters were on the ground. Becca Manlove, a spokeswoman at a fire information line, said the northwest corner of the fire was looking good. Elsewhere, officials were using airplanes and helicopters to drop water on the fire. Crews on the south end were using bulldozers to clear trees and keep the fire from spreading.

Four National Guard helicopters, two water bombers and an air attack plane from Canada were assisting. Crews also were patrolling the fire’s perimeter and monitoring hot spots.

By Wednesday, fire crews had come in from New Jersey, Montana, Nevada, Michigan, Wisconsin and California, Manlove said.

Wednesday’s winds were light, at about 10 to 15 mph with just a few gusts up to 20 mph, said Carol Christenson, a warning coordination meteorologist with the National Weather Service. She said high pressure moving into the area would bring even lighter winds Thursday.

“That’s a far cry from the 30 mph winds that arrived with the cold front,” she said. But the cold front did bring some winter-like temperatures, which will help slow the fire’s spread. A freeze warning is in effect for northeastern Minnesota.

Lows in the area are expected to hit 22 degrees by Thursday morning, she said. Some sleet fell briefly in the area on Wednesday, and it snowed lightly, but no measurable precipitation was in the forecast until Sunday. Even that was estimated to bring less than an inch, Christenson said.

“It’s helping,” Manlove said of the small snow shower Wednesday. “It’s not anywhere near a wet blanket on the fire by any means. Three days of a nice, solid rain would be nicer than that little shower.”

Friday’s forecast calls for warmer temperatures, with a high around 60, less humidity and wind from the south, with gusts of 20 mph. Winds from the south would be significant, because that would push the fire north, taking pressure off Isabella.

“Everyone is kind of keeping their eye on that,” Manlove said. “It’s certainly not a repeat of the conditions we saw on Monday, but it’s fire so we pay attention.”

She said officials get weather updates from the field several times daily.

Reichenbach said officials were encouraged by Wednesday’s decreased winds and lower temperatures. She said colder temperatures help keep moisture in place, and the shorter daylight hours mean the fuels have less time to dry out during the day.

Manlove said the fire would not likely be extinguished until there was what firefighters call “a season-ending event,” meaning a lot of rain or a heavy snowfall.

As of midday, more than 30 entry points into the Boundary Waters Canoe Area Wilderness were closed — less than half of the overall access points, Reichenbach said.

The fire, called the Pagami Creek fire, is south of the area where millions of trees were toppled in a July 4, 1999 windstorm. Shedd said if the fire continues moving eastward, those dried out trees in the blowdown area — which could create more fuel if ignited — won’t be an issue.

One cabin used for storage by the Department of Natural Resources was burned, but no major buildings have burned and no injuries have been reported, even after the fire raced 16 miles in a single day from Monday to Tuesday. The 200 some residents of Isabella — about 8 miles from the fire — were ready to evacuate if needed.

Residents who attended the community meeting looked concerned, and had questions about how an evacuation would work. Officials told them the fire was being closely monitored, and in the event of an evacuation, officials would go door to door in teams of two and hang fliers at residences if people were not home.

Eighty-three-year-old Vera Kuehl, of the nearby town of Finland, said she is ready. Her children helped her load her safe full of important papers into her car.

“We’ve had fires before, but not like this,” she said.

Her daughter, 57-year-old Harriet Moen, had been nervously watching the fire and said her sewing machine, marriage license, and ATV’s were ready to go at a moment’s notice.

“My van is full of photos,” she said.

The Boundary Waters wilderness is popular with canoe campers. About 120 campers were evacuated from the fire zone earlier this week, some by Forest Service float planes.

While the latest fire has grown quickly, it has done less damage than the 2007 Ham Lake fire, which destroyed nearly 150 buildings worth more than $10 million as it raced across 118 square miles in Minnesota and Canada. A fire in Red Lake in 1931 consumed about 1,550 square miles and killed four people.