The Knolls Fire, burning in a remote portion of the San Juan National Forest southwest of Lone Mesa State Park, grew from 70 acres to 317 acres on Thursday, reported Ann Bond, of the San Juan National Forest on Friday.

The fire was started by lightning and was reported to forest officials Wednesday at noon. The low-intensity fire is burning forest litter, open fields and oak brush in a mixed ponderosa pine and aspen forest at about 8,200 feet elevation.

Forest officials say the fire is being actively managed to play its role in making forests more resilient to future fire, insects and disease.

A crew of 15 firefighters and two engines from the U.S. Forest Service and Bureau of Land Management responded on Thursday to conduct burnout operations to confine the fire within a predetermined area.

A slow-moving weather system moving into the area today is expected to bring rain and snow to the area at least through tomorrow.

“We managed this fire with the expectation this weather would be moving in,” said Matt Traynham, Dolores District fire engine captain. “The wet weather will either put the fire out or put it to sleep for a while. Fire activity has already begun to greatly diminish, as expected.”

Fire crews and engines will remain on-site to make sure the fire stays within the confinement area surrounded by forest roads, but fire activity and resulting smoke is expected to greatly diminish over the weekend.

Derek Padilla, Dolores District Ranger, said as long as the fire stays within management parameters and remains low-intensity, it will be allowed to burn. There are no structures in the area. The fire is generally moving in a southwesterly direction.

For naturally caused fires, the forest has the option to let it burn for ecologically benefits.

“We won’t actively suppress it unless activity really picks up,” Padilla said. “When weather conditions and the time of year are aligned, we take advantage of natural ignitions to allow fires to do their thing: reduce fuels, recycle nutrients, and mitigate against future fires.”

Patrick Seekins, Dolores District fire management officer, said the natural fire was needed for the overgrown section of forest.

“This is a good fire. Our forests are in bad shape right now. The understory is so choked up with vegetation you can hardly walk through it. ... If a fire is caused by lightning, it’s nature’s way of saying, ‘This area needs to burn,’” he said.

Crews are managing the fire in the same way they did the Long Draw Fire, which burned about 300 acres near Lone Mesa State Park in June. Firefighters will set controlled burns along the roads to keep the fire from spreading, and allow it to burn itself out. Crews are currently focusing operations and patrols along the Dry Canyon Road (Forest Road 510), which is south of the Salter Y intersection and Forest Road 514. Undeveloped private land exists two miles to the north, and firefighters are focusing efforts to make sure the fire does not spread in that direction. Crews will continue to patrol the area as long as the fire burns.

Smoke is expected to be visible from the Dolores-Norwood Road (Forest Road 526), Forest Road 514, and from Cortez and Dove Creek along Colorado Highways 145 and 184 and U.S. Highway 491.

Travel should not be affected on roads in the area, except for Forest Road 510 and possibly Forest Road 514 at times because of smoke. Roadside signs will be posted alerting the public to fire operations. Night-time smoke may settle downslope in valleys to the south within the McPhee Reservoir area, along Colorado 184 and portions of Colorado 145 in the Dolores River Canyon.

Seekins expected the fire to cover 200 to 300 acres by Thursday night, but with heavy rain in the forecast for Friday, he said there wasn’t much risk that it would burn out of control.

Montezuma County and the surrounding areas have seen unusually warm, dry weather this fall, which might have contributed to the fire’s spread. Meteorologist Jim Andrus, of Cortez, said he only measured 5 percent of the normal rainfall for the area this October.

“The weather has been much warmer than normal this year, and we’ve received very little rain,” he said. “I’m sure the forest up there is quite dry.”

He said he wouldn’t be too surprised if there were more small fires in the area before winter. According to the Cortez Fire Protection District’s website, the current fire danger is “high.”