The John Peperakis papers (1913-1990) contains correspondence, mining information, and mostly maps that are hand-drawn, originals documenting mining (coal) areas in Utah and the Rocky Mountain areas. Peperakis was a mining engineer who was manager of Sunnyside Coal Mines, Utah for Kaiser Steel Corporation.
The Harold F. Silver papers (1941-1998) contains financial records of the Silver Corporation, requests for charitable contributions, documents relating to the sale of sugar processing machinery patents to American Factors Associates, and drawings of a continuous coal mining machine designed by Silver and built by Silver Engineering Works (1941-1946). Silver was a Utah and Colorado inventor, businessman, philanthropist and civic leader. He invented the continuous coal miner, a non-flammable dry cleaning process, and various machines for processing sugar beets.