Volcanic hazards at Glacier Peak result from several different phenomena: tephra fall, pyroclastic flows, pyroclastic surges, ballistic ejection, debris avalanches, lahars, and floods. Lahars represent the greatest hazard, followed by tephra fall. We describe each of these phenomena, the damage it can cause, its history of occurrence at Glacier Peak (if known), and where around Glacier Peak that damage is most likely to occur.