We're armed with crampons, ice axes, rope, GPS receivers, and bear spray to ward off grizzlies, and we're trudging toward Sperry Glacier in Glacier National ... an amusement park fun house.

On the night of August 12, 1967, grizzly bears in Glacier National Park killed two young women and severely mauled one man. For everyone involved, it remains an unforgettable night of crisis ...