Prescribed burns continued Thursday near Big Sky as part of the U.S. Forest Service's Aspen Restoration projects.
In total 90 acres will be burned at a site in Durnam Meadow, which was lit on Tuesday.
Montana has lost 64 percent of its aspen trees over the last century, according to the U.S. Forest Service.
Officials say prescribed burns are meant to stimulate aspen tree roots.
"If we don't have prescribed fire during the spring and fall and moderate those intensities, eventually what will happen is that will turn into a wildfire at higher intensity," said the project’s burn boss, James Ray.
As of Thursday, Ray estimated about two-thirds of the surrounding pine trees were cut and half the burning done.
Ray said it’s common for deer, elk and moose to graze on aspen, and because of their high moisture content they can act as natural barriers during wildfires.
"Aspen's what they call a cornerstone in the ecosystem," Ray said.
Ray said aspen trees need wildfires and disturbance to regenerate and repopulate, and over the years competing species like pine trees have crowded them out.
After the pine trees are cut down and burned they’re left on the ground as barriers from wildlife, Ray added. This enables the new aspen stands to fully grow.
Ray said the clock is ticking.
"Most of the aspen we see here is mature, older aspen that's at the end of its life cycle. So if we don't do anything to stimulate this aspen, it's going to go away, and no future generations are going to be able to appreciate the aspen we have now," he said.
The Gallatin National Forest plans on expanding the burn projects up and down the Gallatin Valley with the hope it leads to huge corridors of aspen tress in the next 15 years.