Reno Sales (1876-1969) was an Anaconda Company mining geologist, known as "The Father of Mining Geology." Papers include a biographical sketch by Vincent D. Perry and Charles Mayer; incoming and outgoing correspondence (1957-1967); diaries (1911, 1920-1968); writings; and miscellany. The Valley Ditch Company subgroup includes correspondence (1957-1966), financial records (1945-1966), minutes (1906-1964) and other materials.