Department of Transportation. Office of Community Relations Official photographs: Thistle disaster documentation, 1983-1984.

Utah Department of Transportation (UDOT) Community Relations personnel documented the Thistle Disaster of 1983-1984. Thistle, originally the name of a town, became a term used to describe a massive mud slide which created a natural dam across the Spanish Fork River and destroyed the town of Thistle. UDOT Photographic Services Director, Gerald E. Peterson, took hundreds of photographs of the Thistle area from April 1983 to May 1984. This collection not only documents the disaster and subsequent reconstruction, but also includes photographs of Thistle before the disaster.

Documentation of the disaster began in April 1983 after heavy precipitation caused instability in the earth. UDOT crews initially responded to reports that shifting earth had left huge cracks in U.S. Highway 6. Shortly the giant slide, moving at 6-18 inches an hour, dumped more than one million cubic yards of earth over the highway and destroyed the Denver and Rio Grande Western railroad tracks. Highway crews wereunable to save either the road or the tracks as the mud mountain continued to slide from early April into May. The massive slide created a natural dam across the Spanish Fork River, and the dam in turn created Thistle Lake which completely submerged and destroyed the town of Thistle. The U.S. Corp of Engineers, the Utah National Guard and construction workers from many companies joined UDOT workers in response to the Thistle slide. Both Governor Scott Matheson and President Ronald Reagan declared the slide a disaster area. Efforts to control the slide turned to reconstruction of rail and roadways, and to the construction of a drainage tunnel which would control drainage of Thistle Lake. Throughout the reclamation and reconstruction process workers were concerned about the questionable stability of the natural dam, with subsequent slides, and the general instability of the earth in the area.