The extreme scorching heat of the sudden blowup can be attributed to the expansive Western white pine forests that covered much of northern Idaho at the time. Hydrocarbons in the trees' resinous sap boiled out and created a cloud of highly flammable gas that blanketed hundreds of square miles, which then spontaneously detonated dozens of times, each time sending tongues of flame thousands of feet into the sky and creating a rolling wave of fire that destroyed anything and everything in its path.[12]