From Wikipedia
Thistle is a ghost town in Utah County, Utah, United States, about 65 miles (105 km) southeast of Salt Lake City. During the era of steam locomotives, the town's primary industry was servicing trains for the Denver and Rio Grande Western Railroad (often shortened to D&RG, D&RGW or Rio Grande). The fortunes of the town were closely linked with those of the railroad until the changeover to diesel locomotives, when the town started to decline.
In April 1983, a massive landslide (known as a slump) dammed the Spanish Fork River. The residents were evacuated as nearly 65,000 acre feet (80,000,000 m3) of water backed up, flooding the town. Thistle was almost completely destroyed; only a few structures were left partially standing. Federal and state government agencies have claimed this was the most costly landslide in United States history, the economic consequences of which affected the entire region. The landslide resulted in the first presidentially declared disaster area in the state of Utah.
U.S. Route 6 (US-6), US-89 and the railroad (now part of Union Pacific Railroad's Central Corridor) were closed for several months, until they were rebuilt on a higher alignment overlooking the area. The remains of Thistle are visible from a rest area along US-6 or from the California Zephyr passenger train.