At the end of summer in southern Oregon's Cascade foothills, when trees and brush have turned tinder dry and thunderstorms regularly roll overhead, Millie Chatterton and her neighbors start thinking about the lightning strike that could touch off disaster. The Biscuit burns in 2002. Photo: USFWS. Chatterton can't forget the afternoon in 1987 when she walked out of a grocery store in her town, Cave Junction, and saw a "big atomic mushroom cloud" of smoke blossoming on the horizon. Later, she watched the lightning-caused wildfire "blowing up trees one after another" on federal property near her own five acres. That …