Which is to say, logging and burning do different things. Logging physically removes biomass; fire chemically changes it. Logging takes the big stuff and leaves the little; fire burns the little stuff and leaves the big. After a crown fire—a fire that flashes through a forest canopy—what remains are the tree trunks that logging would have hauled off. Removing them earlier would have lathered the land with post-cut debris called slash—exactly the kind of volatile fuel that fire favors. Slash disposal, in turn, typically means burning it, which has its own hazards for escape fires and which fills the sky with noxious smoke. Up until recent decades, the great conflagrations of American history have, with almost preternatural cunning, trailed logging and land-clearing.