The Thistle Mudslide

A giant landslide in April 1983 obliterated the tiny town of Thistle in Utah County.

In 1983, the most costly landslide in US history swept down on the tiny town of Thistle, damming up the Spanish Fork River, and severing the rail line that connects Salt Lake City with Denver. Winter and spring had been extraordinarily wet along the Wasatch Front that year. Rain saturated the ground, and late snowfalls melted quickly to destabilize mountain slopes.

The slide first began to move on Wednesday, April 13th. Employees of the Denver and Rio Grande Western Railroad had been watching the area closely, and were surprised to find that the railroad tracks had shifted several inches. Over the next few days, the tracks continued to move and the surface of Highway 6 started to buckle. By Friday, the road had been closed and railroad executives had decided to reroute trains going from Salt Lake to Colorado. Now, state and railroad officials could concentrate on keeping the river channel open. Crews dredged the river around the clock, but they were fighting a losing battle.

By Sunday, Thistle's fate was sealed. Officials abandoned the idea of keeping the streambed open; the slide was simply moving too fast to keep up with it. Residents were ordered to evacuate, and within a few days the slide had completely closed off the river, causing water to build up behind the artificial dam and bury the town. Eventually, the railroad and highway reopened away from the slide, but the town of Thistle was never resurrected. It remains a ghost town. The worst natural disaster in Utah history, the Thistle mudslide ended up costing the Denver and Rio Grande Western Railroad and the State of Utah over $200 million dollars.