| 1. |  | Rist Canyon Flood | Rist Canyon (Colo.); Flood damage--Colorado--Larimer County--History; Roads--Colorado--Larimer County | Rist Canyon Flood, water erosion of Rist Canyon Road. 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... |