of 1873 and the railroad was now moving into the northern half of the Cache Valley where there were fewer Mormon volunteers due to this area only recently having been relinquished by the Bannock and Shoshone. Poor decisions by the planners and the lack of business from the frugal residents of the Cache Valley led to the bankruptcy and foreclosure sale of the Utah Northern only a few years later in 1878. Robber baron Jay Gould transformed the Utah Northern. He and Union Pacific acquired the Utah Northern Railroad, changing the name to the Utah & Northern Railway and infused the railroad with capital. Big business knew that an electrical age was coming and that the demand for copper products was putting pressure on copper prices. They knew that there were rich copper deposits at the mines near Butte, Montana. Union Pacific quickly resumed construction on the Utah & Northern Railway after purchase in April 1878. Jay Gould invested personal money to get construction started just beyond Franklin in the fall of 1877. The new plan was not to build the road to Soda Springs, but to build a longer road on a direct route through the Cache Valley, then north across eastern Idaho and north across western Montana to Butte, Montana. In the first year of construction, they reached Eagle Rock (now Idaho Falls, Idaho), north of the Utah/Idaho border, where they built a bridge across the Snake River in early 1879. In the second year, they added another of track and crossed the continental divide at the Idaho/Montana border. After three and a half years of construction, before the close of 1881, they completed the additional of road to Butte, Montana. Butte became the largest copper producing city in the world and Butte's population, by some estimates, grew to nearly 100,000. This made Butte, with its "Copper Kings," the second largest city in the West with more influence than Salt Lake City, Denver, Sacramento, Seattle, or Portland. Only San Francisco remained larger and more important. Butte, with its large-scale mining and smelting operations, was dubbed the Pittsburg of the West. The Utah & Northern was switched from narrow gauge to on July 25, 1887 only six years after completing the line to Butte. The railroad operated successfully for several years and finally became a branch of the Union Pacific Railroad. See also Utah Central Railroad (1869–81) Utah Southern