 Complete the following phrase:  Between the years 1970 and 2012, Shoshone National Forest averaged 25 fires annually, of which half were due to natural ignition from lightning, which accounted for 90 percent of the total acreage burned. The remaining acreage that burned was due to campfires that got out of control or from other causes. In Shoshone National Forest, the highest fire incidence is generally in the months of August and September. An average of burns annually, with the worst year in the past century being 1988, when burned from fires that had spread from the conflagration that engulfed Yellowstone National Park and the surrounding region. After the 