This route was carved by the tributaries of the Price River on the eastern side of the mountains and the Spanish Fork on the west.

[12] 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.

Fifth-generation descendants of the Pace settlers continued to operate a family-owned cattle ranch until the town was evacuated.

[9]: 99  Other settlers included Mormons who originally settled elsewhere in Utah but subsequently arrived to homestead fertile ground on Billies Mountain, on the north wall of the canyon.

A small group of Utes inhabiting the canyon frequently raided the newcomers, and as a result were forcibly relocated in the 1870s.

[9]: 94 & 118 The first railroad track laid through Thistle was a narrow-gauge spur line servicing coal mines near today's Scofield Reservoir, built in 1878 by the Utah and Pleasant Valley Railway.

The D&RGW connected this line with one they had built west from Colorado, completing a link from Salt Lake City to Denver.

[15]: 157 The railroad built several facilities in Thistle to service and prepare trains for the change in grade and curvature of the line.

The growth of Thistle was closely tied to the success of the Denver and Rio Grande Railroad throughout the era of steam locomotives.

The town's railroad infrastructure included a five-stall roundhouse, depot, machine shop, and structures to restock passing trains with sand, coal and water.

Non-railroad infrastructure included general stores, a post office, barber shop, saloon, pool hall, bakeries and restaurants.

Thistle was listed in a book of Utah ghost towns published 1972, with the author noting most of the remaining buildings were abandoned with a handful of permanent residents in the city.

[12] Rio Grande maintenance personnel began noticing unstable ground downstream from Thistle years before the landslide occurred.

On April 13, the division track master flew to Denver to explain the situation at a specially-called staff meeting.

All trains were limited to speeds less than 10 miles per hour (16 km/h), and were accompanied by maintenance personnel who had to continually work to keep the tracks in line.

The last train to pass through downtown Thistle was the westbound Rio Grande Zephyr, on April 14, 1983 at about 8:30 p.m. That night, both US‑6/US‑89 and the rail line were closed.

All through trains between Denver and Salt Lake City were rerouted to Union Pacific Railroad's Overland Route through Wyoming.

Both the highway and railroad would be re-routed by blasting a path scaling the north wall of Spanish Fork Canyon.

[5] The landslide eventually formed a dam that created a lake three miles (5 km) long and over 200 ft (60 m) deep.

[7] Concerned the dam could fail, the state of Utah decided to build a tunnel to re-route the flow of the river.

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.

Some people who lived and worked on opposite sides of the landslide area suddenly had commutes exceeding 100 miles (160 km).

It specifically noted an increase of coal hauling trucks on highways and streets in the area due to the loss of rail access.

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.

Motorists saw a relocation with several mountain cuts built high up the canyon wall, with a view of the slide and former lake.

During this time, the state stationed two full-time watches at the cuts, who would close the road while falling rocks were cleared.

[27] The pending completion of the again-rebuilt US‑6/US‑89, with properly laid asphalt and stable rock cuts, was announced in November 1984, 18 months after the closure of the original alignment.

[27][28] Starting in 1993, the Utah Department of Transportation began discussions with former Thistle residents to build a memorial to the town.

Pre-historic landslides created the more gentle slopes that made the area usable as a transportation corridor across the Wasatch Mountains.