The helicopter circled over a small fire in the Frank Church-River of No Return Wilderness, near the border between Idaho and Montana. It was the summer of 2013 and Dave Campbell, the U.S. Forest Service district ranger responsible for the wilderness, peered down, trying to decide how far the fire would spread.

Based on his observations of hundreds of fires in the area, he believed it would probably burn down a hill and stall out on the banks of the Selway River. The computer models backed up his prediction, so Campbell decided to let it burn. [Read more…]