Coal seams lie beneath Rock Springs, and in 1850 Howard Stansbury noted coal near the present town. After the Union Pacific Railroad was built through the area in 1868, large commercial mines opened. Number 1 Mine, opened downtown, and the nearby Blair Mine, which opened in the early to mid 1860's, formed the nucleus of an infant community whose streets were said to have been laid out by a "drunken" miner on a dying horse. The town became known as the "Newcastle of the West," after the famed English coal town. From 1868 until the mid-twentieth century, coal from Rock Springs area mines provided relatively clean-burning fuel for steam locomotives crossing the Rocky Mountains. In the late 1800's, English, Swedish, Finnish, Chinese, Italian, and Slovenian miners came to work in the mines, and by the turn of the century Japanese, Welsh, Cornish, Scottish, German, and Polish workers had joined others there, making Rock Springs one of the most diverse communities in Wyoming. When the underground coal mines closed in the 1950s, many thought Rock Springs would vanish, but newly opened trona mines west of present Green River employed many miners who stayed. In the 1970's, strip mines opened east and north of present Point of Rocks, and coal mining again provided jobs. Coal has been mined around Rock Springs from 1862 to the present, bringing the town to life and continuing to fuel the area's economy.