Gregory Alan Williams

 (born June 12, 1956) is an american voice actor. In Fallout 3 he voices Lucas Simms, and in Fallout: New Vegas he voices Bruce Isaac, The Lonesome Drifter, Cliff Briscoe, Corporal William Farber, Trent Bascom, Don Hostetler, Cook-Cook, Keith, George, Bill Ronte, Dead Sea, Severus, Karl, Mister Holdout, and additional characters.