The thousands of visitors and campers in Colorado’s Big Thompson Canyon had only minutes to find higher ground.
Around dinner time on July 31, 1976, a storm system stalled high in the sky above the center of the canyon, which stretches between Estes Park and Loveland. Over the course of an hour, the clouds unleashed more than 7 inches of rain, swelling the river encased in the narrow canyon by a foot every three minutes.
By the end of the storm the following day, the system had dumped the equivalent of the area’s normal yearly rainfall on the canyon…