The trade route on which Thistle lies was used by
Indian tribes before the arrival of European settlers; two
Ute chiefs,
Taby and
Peteetneet, led tribal migrations through the canyon each spring and fall. Most of Thistle's residents were railroad employees sent to live in the town, but there were some who had settled before the railroads arrived. The first settlers were part of the
Mormon migration to Utah, and the first of these was the Pace family, who migrated from
Nauvoo,
Illinois, reaching Thistle in 1848. Fifth-generation descendants of the Pace settlers continued to operate a family-owned
cattle ranch until the town was evacuated. The railroad built several facilities in Thistle to service and prepare trains for the change in
grade and curvature of the line. The railroad placed
helper engines on eastbound trains at Thistle for the ascent to Soldier Summit. The town provided a meal service for the trains until the use of on-board
dining cars eliminated the need for meal stops. By 1983, only a few families remained in Thistle. River past the dam formed by the Thistle landslide, July 2015 Governor
Scott Matheson requested federal aid to deal with the situation. After a visit to the area by the director of the
Federal Emergency Management Agency, U.S. president
Ronald Reagan issued the first presidential
disaster area declaration for the state of Utah. The landslide eventually formed a dam that created a lake long and over deep. In the years following, the former residents of Thistle filed various lawsuits to recover their losses. In one, they claimed that their property was taken to rebuild the road and railroad without just compensation. Another lawsuit claimed negligence on the part of the D&RGW. The residents argued that the railroad's maintenance workers knew the ground was unstable; however, they only repaired the track. The residents contended the slide could have been prevented by using a water drainage system to relieve pressure at the head of the unstable area. They further contended that such a system could have been put in place had the railroad thoroughly investigated the problem upon first noticing it. The engineering firm employed by the Rio Grande said that their studies indicated the crown of the landslide was about above the level of the tracks, and that the Rio Grande did not know the true size of the unstable area until the slide was in motion. A jury absolved the D&RGW of responsibility. The plaintiffs appealed the decision, and a second trial in 1993 resulted in a $1.1 million award for the landowners (equivalent to $ million in ). The D&RGW filed suit against the Utah Railway over sharing the costs from the landslide. The Utah Railway had an ownership interest in the line, based on a track-sharing agreement. The economic effects of the closure of these transportation arteries were felt throughout the western United States; the closure devastated rural Utah. The operations of coal mines, uranium mines, turkey farms, animal feed companies,
gypsum mines, and cement and clay factories were severely impacted. At least two trucking firms and one oil-producing firm suspended or ceased operations. Southeastern Utah's tourism industry suffered without access for visitors from the north and west. Some people who lived and worked on opposite sides of the landslide area suddenly had commutes exceeding . The highway patrol temporarily closed a
weigh station at Peerless (a location along the US‑6 corridor near
Helper) and built a temporary weigh station near
Salina (along
I-70 about south of Thistle), which saw a sudden increase in truck traffic. The highway patrol estimated the temporary facilities inspected 57,000 trucks and made 80 arrests. The D&RGW estimated the slide cost them $80 million in lost revenue (equivalent to $ million in ), averaging $1 million for each day that the tracks were out-of-service. This figure included $19 million in payments to the
Union Pacific for the use of their lines.
Highways The new alignment of US‑6/US‑89 was opened on December 30, 1983. The dedication was planned for the next day, but lines of cars formed at the barricades as soon as news broke that the highway was complete. Some were residents anxious to see the area or visit relatives they had not seen since the slide; others were truck drivers frustrated by long detours. The Highway Patrol requested the ceremony be canceled and the highway opened early, as they were unable to disperse the crowds. Starting in 1993, the Utah Department of Transportation began discussions with former Thistle residents to build a memorial to the town. The department maintains a view area overlooking the townsite along US‑6/US‑89.
Coal Hollow fire On August 4, 2018, a lightning bolt sparked a large fire in Spanish Fork Canyon.{{cite web|url=https://www.sltrib.com/news/2018/08/13/coal-hollow-closes-us/|title=Coal Hollow Fire closes U.S. 6 through Spanish Fork Canyon, forces evacuation of Diamond Fork Canyon ==Geology and climate==