The blaze began on August 29, 2012, close to the Yellowstone River; it burned rapidly through the small town of Pine Creek, destroying five homes in the process. It then moved past nearby farms and spread east toward rugged terrain in the Absaroka-Beartooth Wilderness, an area where pine beetles had already taken a toll on the forests. The fire was 51 percent contained by September 21 and had charred 8,509 acres (3,443 hectares).
On September 11, 2012, the National Interagency Fire Center reported that a total of 947,848
acres (383,580 hectares) had burned in Montana since the beginning of the year, about 11 percent of the total burned across the United States. Only two states—Idaho and Oregon—had seen more acres burned by that date in 2012.
In a region that has seen the number of fires and acres burned rise in recent decades, the Bagley fire burned another 46,000 acres of forest in northern California. However, recently published research suggests the severity of fires in the area has remained steady.