The Atlantic City Project: The Iron Ore Boom and Bust

The pit was a hill called Iron Mountain. Crews blasted its taconite, a low-grade iron ore, on three shifts a day until the mountain was a 250-acre hole; magnets pulled the iron from the crushed rock, and dense black pellets left on U.S. Steel's own railroad over South Pass, the last line built across the Continental Divide. Work stopped on October 1, 1983, six months before the official closing the panel gives, and 559 jobs went with it. The pit has filled with water, and its 200-acre tailings basin was capped under the state's abandoned-mine program.

What the plaque says

The Atlantic City Project: The Iron Ore Boom and Bust The hills of the Sweetwater Mining District hold various minerals, and beginning in the 1960s, iron ore mining provided an economic boom for the area. In 1960 the U.S. Steel Corporation broke ground on the nation's highest open pit iron ore mine at 8,300 feet above sea level. By the spring of 1963 the complex was in full swing. Employees operated an open pit mine, an ore crushing and screening facility, a concentrating plant and water storage and handling system, and storage, loading, and shipping facilities. A Union Pacific Railroad spur carried the processed ore to Winton Junction, ten miles north of Rock Springs, where it connected with the main line and rolled to the Geneva Steel Works in Provo, Utah and was converted into a variety of high-grade steel products. The mine produced more than 90 million tons of iron ore by the time U.S. Steel closed the mine in the spring of 1984, effectively busting the iron ore industry in this region.

Where it stands

Worth the stop nearby

• South Pass City State Historic Site — 4.5 mi
  The Carissa lode built the town in a year; the mine outlived the boom by eight decades, and its mill runs again for visitors.
• Sinks Canyon State Park — 15 mi
  A river that vanishes into a limestone cave and comes back a quarter mile on, slower than it should, warmer, and with more water than went in.

More markers nearby

• Fort Stambaugh, 1870-1878 — 1.8 mi
• Miners Delight: The Boom's Broken Promises — 2.0 mi
• Atlantic City: Surviving the Bust — 2.5 mi
• South Pass and South Pass City — 3.4 mi