The Colorado Fuel and Iron Company (CF&I) was a large steel conglomerate founded by the merger of previous business interests in 1892. By 1903, it was mainly owned and controlled by John D. Rockefeller and Jay Gould's financial heirs. While it came to control many plants throughout the country, its main plant was a steel mill on the south side of Pueblo, Colorado and was the city's main industry for most of its history. From 1901 to 1912, Colorado Fuel and Iron was one of the Dow Jones Industrials. The steel-market crash of 1982 lead to the decline of the company. After going through several bankruptcies, the company was acquired by Oregon Steel Mills in 1993, and changed its name to Rocky Mountain Steel Mills. In January 2007, along with the rest of Oregon Steel's holdings, was acquired by EVRAZ Group, a Russian steel corporation, for $2.3 billion.
Through the process of vertical integration, the company came to own more than just the main steel plant. Over the course of a century, CF&I operated coal mines throughout southern Colorado, as well as iron mines in Wyoming and Utah, limestone quarries, smaller mines for other materials going into the steel making process, and the Colorado and Wyoming Railway. In Redstone, Colorado, hundreds of coking ovens converted coal into coke.
The Mcnally, Cameron, Robinson and Walsen Mines located in the area of Walsenburg, Colorado, were just a few of the mines owned by the Colorado Fuel and Iron Company.