As a result of an extended period of abnormally high precipitation, prolonged snow melt, and subsequent high water tales, Utahns, in 1983 suffered from landslides, debris flows, flooding, and a dam failure. On April 30, 1983, the President determined the Spanish Fork slide-dam and Thistle flood covering Utah, Carbon, and Emery Counties was of sufficient seventy and magnitude to issue a Major Disaster Declaration under Public Law 93-288. The incident period was not closed until July 1, 1983. By the time all flooding had ceased, nineteen additional counties (over 75% of Utah) had been included in the Declaration.
Team, Hazard Mitigation (Utah), "Interagency Hazard Mitigation: 90-Day Post Flood Recovery Progress Report" (1983). Elusive Documents. Paper 17.