| 1. |  | Big Thompson Flood | Flood damage--Colorado--Big Thompson Canyon; Big Thompson River Flood, Larimer County, Colo., July 31, 1976; Dwellings--Colorado--Big Thompson Canyon | Aftermath of Big Thompson Flood, house in background. The Big Thompson Canyon flood on July 31, 1976 occurred when a thunderstorm stalled over the canyon dropping twelve inches of rain during a four hour... |