What started as an exhibition to entertain audiences has turned into the most popular-and dangerous-event in rodeo: bull riding. When a 150-pound man attempts to ride a two-ton bull with a killer instinct, it's not a matter of whether the rider will get injured, but when, and how badly. As cowboy Jim Shoulders says, "You can't stop something like an injury from hurtin', but you can damn well not let it bother you." What motivates riders to devote themselves to this challenging sport? Gail Woerner covers bull riding from its beginning into the new millennium.