This collection consists of correspondence (1901, 1913, 1924) including letters by Nancy Russell discussing illustrations for A Most Desperate Situation; a typescript of a diary (1881) kept by Cooper during the West Gallatin Pacific Exploring Expedition; financial records (1904-1911) regarding lead ore shipping; a speech (1907) given by Cooper to the Gallatin County Pioneer regarding W.W. Alderson); writings (1910) including handwritten and typescript versions of A Most Desperate Situation; ephemera (1883-1906) from Montana Constitutional Conventions, the Northern Pacific Railway; and the World's Columbian Exposition; and clippings (1902-1924) regarding the Montana Pioneer's Reunions.