Kiewit Mining Group traces its roots to the early 1940s. At that time, Kiewit was building highways across the plains and Rocky Mountains. Once the company had developed a concentration of resources in the west, it established a district office in Sheridan, Wyoming. In 1943, Kiewit managers spotted the opportunity to keep existing construction employees and equipment productive throughout the winter by launching a new technique, "surface coal mining", outside of Sheridan. Because all area coal mines prior to that time had existed as underground operations, Kiewit became a pioneer in the industry. With this new technique, Kiewit established Big Horn Coal Company. As other mines in the area followed suit, the face of coal mining was changed forever.
During the 60s and 70s, Kiewit continued to grow its coal mining business with the development of Rosebud Coal Sales Company and Black Butte Coal Company both located in Wyoming, and Decker Coal Company in Montana. In the 1970s, Decker was one of North America’s largest surface mines. It produced more than 10 million tons of coal per year. With high production coming from these four surface coal mines, Kiewit Mining Group was formed as a new business subsidiary.
Kiewit Mining Group’s other coal mining operations are Walnut Creek Mining Company and the San Miguel Mine in Texas, and Buckskin Mining Company in Wyoming. Kiewit Mining Group has diversified its mining ventures to include a phosphate operation in southeast Idaho and in the Oil Sand Regions of Alberta Canada. Contract mining continues to broaden Kiewit Mining Group’s expertise, personnel and equipment. To date, through its mining operations and mine management, Kiewit Mining Group has been involved in moving more than 4.5 billion cubic yards of overburden and coal, and is recognized as one of the top 10 coal producers in the nation.
Reclamation has been completed at Big Horn and Rosebud. In fact, Kiewit Mining Group began reclamation efforts before the practice was regulated by the federal government.