The Hillary W. St. Clair papers (1896-1997) contain some of St. Clair's published research, calculations, notes and workbooks during his time with the Bureau of Mines, and other research in the field of metals and mining. Materials of particular interest include St. Clair's notes and lecture material regarding the history of American mining. This was later published by the Bureau of Mines in a book called Mineral Industry in Early America.