Due to a 300 foot high landslide and upheaval that blocked Rio Grande's Denver to Salt Lake City mainline, US Highway 6, and the Spanish Fork River, construction crews worked around the clock to drill the first of two tunnels through Billy's Mountain at Thistle, Utah. The line relocation become necessary by April 15, 1983, when after two consecutive wet winters, it became physically impossible to keep the tracks open through the tiny town of Thistle. Pictured at the end of the day on May 22nd, construction of the 3009 foot Thistle Tunnel continues. After the Denver-Salt Lake City mainline had been closed for 81 days, it reopened for service on July 4. This unprecedented natural disaster was the most expensive in United States history at the time. The D&RGW's expenditure to relocate the track was $45 million plus $80 million in lost revenue and $19 million to utilize trackage rights on UP's Overland Route through Wyoming to Denver. Kodachrome 25 transparency photographed with the permission of the D&RGW Utah Division Engineer.
