FLATHEAD RESERVATION — The end of November also marked the end of open burning season in Western Montana. During the summer months, open burning is allowed by obtaining necessary permits, but because of colder weather conditions, comes to an end during the winter.

“In Western Montana, we’re subject to inversions,” Jim Clairmont, training coordinator with the CSKT Division of Fire, said. “Cold air gets trapped against the ground by warm air above. The smoke rises up to the inversion level and ends up smoking out the valley.”

Western Montana is especially susceptible to inversions because of the mountainous terrain. The smoke from burning becomes trapped in the valley, diminishing air quality.

Illegal open burning carries up to a $500 fine, as well as the cost of putting out the fire. Open burning season resumes on March 1, 2012.