The Snow Ranch Fire burning 11 miles west of Pagosa Springs in the Chris Mountain area of the San Juan National Forest, which stayed between 2-3 acres for the first two days, had spread to 45 acres and was zero percent contained as on Thursday afternoon.

The lightning strike fire was discovered Tuesday morning and began roughly a mile from a transmission line that provides power to all of Archuleta County, said Andy Lyon, spokesman for the San Juan National Forest.

“If the fire were to take that out, a lot of people would be in the dark here in Pagosa,” Lyon said.

The Forest Service has mapped out a 400-acre containment zone for which it will allow the fire to expand into.

The Forest Service began bulldozing around the perimeter of the containment zone on Wednesday, and began blacklining – burning a control line – around the perimeter on Thursday. Both tactics deprive the fire of fuel and stop the blaze’s spread if it approaches containment lines.

Blacklining generates smoke, which Lyon said combined with smoke already rising from the 45-acre fire. A plume was visible from U.S. Highway 160 as well as from Pagosa Springs, Bayfield and even southern Durango under clear conditions.

Lyon said the Forest Service is allowing the small lighting-caused fire to expand as a way to manage forest health and prevent catastrophic wildfires in the future.

Periodic small fires, often caused by lighting strikes, are necessary within many forest ecosystems to eliminate the overabundance of underbrush that fuels larger, catastrophic fires, Lyon said.

However, for nearly a century, mainstream ecology was unaware of this principle. Instead, the Forest Service operated off the notion that every fire should be contained and extinguished to as small of area as possible and as quickly as possible.

“There'd be a lightning strike, we'd go put it out,” Lyon said. “All of the dead trees, all of the pine cones, all of the leaves, all of the needles just kept building up.”

That led to an overabundance of underbrush. Meanwhile, the Western U.S. has become hotter and drier, which has contributed to the increasing frequency of massive, headline-making wildfires over the past few decades.

The Forest Service is confident in allowing the fire to expand because the area was logged about a decade ago, meaning fuels are relatively sparse.

“We’re going to get lightning strikes, maybe tomorrow, maybe a year from tomorrow,” Lyon said. “And on a hot, windy day in August if a fire comes out of the forest and reaches this 400 acres, now it's not going to have as much to burn.”

Lyon said the blacklining efforts were expected to be completed Thursday, wind permitting. After that, the roughly 100 firefighters on scene will commit to holding the line of the containment zone.

Jeff Colton, a National Weather Service meteorologist sent to assist the Forest Service with the Snow Ranch Fire, said conditions in the area for the past two days have been hot and dry. Showers and thunderstorms were expected to roll in Friday from Arizona and settle over Southwest Colorado, which will help suppress the fire but also raise the risk of wind gusts up to 50 mph.

“It depends on where the winds materialize,” Colton said. “But that area is pretty isolated.”