The Stand.

"For a long time—ten years, at least—I had wanted to write a fantasy epic like The Lord of the Rings, only with an American setting. I just couldn't figure out how to do it. Then . . . after my wife and kids and I moved to Boulder, Colorado, I saw a 60 Minutes segment on CBW (chemical-biological warfare). I never forgot the gruesome footage of the test mice shuddering, convulsing, and dying, all in twenty seconds or less. That got me remembering a chemical spill in Utah, that killed a bunch of sheep (these were canisters on their way to some burial ground; they fell off the truck and ruptured). I remembered a news reporter saying, 'If the winds had been blowing the other way, there was Salt Lake City.' This incident later served as the basis of a movie called Rage, starring George C. Scott, but before it was released, I was deep into The Stand, finally writing my American fantasy epic, set in a plague-decimated USA. Only instead of a hobbit, my hero was a Texan named Stu Redman, and instead of a Dark Lord, my villain was a ruthless drifter and supernatural madman named Randall Flagg. The land of Mordor ('where the shadows lie,' according to Tolkien) was played by Las Vegas" (Stephen King, The Stand: Complete and Uncut).