|Summary:||The I. D. O'Donnell Papers include diaries, correspondence, business records, literary manuscripts, postcard albums, subject files, and photographs. Correspondence includes letters from Montana State College, the U. S. Department of Agriculture, U. S. Reclamation Service, U. S. House and Senate Committees on Beet Sugar Industry, Montana Irrigation and Drainage Institute, and the Secretary of the Interior, Franklin K. Lane. O'Donnell received letters from Montana political leaders such as Under Secretary of the Department of Agriculture M. L. Wilson, U. S. Senators Thomas J. Walsh and Henry L. Myers, U. S. Representative John M. Evans, and Governors J. E. Erickson and F. H. Cooney. Manuscripts include articles on agriculture, livestock, and farm management, and the column "Hints from the Practical Farmer" written for the Reclamation Record, as well as manuscripts O'Donnell collected for research on topics such as alfalfa, birds, irrigation, sugar beets, dairy cattle, soil, weeds, ranch management, and hogs. O'Donnell also collected material on topics such as Billings and Montana history, various irrigation projects in Montana, and agriculture. The collection also contains business records from the Minnesota and Montana Land and Improvement Company, the Frederick Billings estate, and the Hesper Farm. The collection also contains postcards and travel brochures from O'Donnell's various travels.