On any given day last summer, the smoke-choked skies over Missoula, Montana, swarmed with an average of twenty-eight helicopters and eighteen fixed-wing craft, a blitz waged against Lolo Peak, Rice Ridge, and ninety-six other wildfires in the Lolo National Forest. On the ground, forty or fifty twenty-person handcrews were deployed, alongside hundreds of fire engines and bulldozers. In the battle against Rice Ridge alone, the Air Force, handcrews, loggers, dozers, parachutists, flacks, forecasters, and cooks amounted to some nine hundred people.

Rice Ridge was what is known as a mega-fire, a recently coined term for blazes that cover more…