This collection contains papers of and relating to Joel Palmer and his family that were compiled by the Oregon Historical Society Research Library over the course of a century. The papers are a mix of original documents, typescript copies, photocopies, and photostat reproductions.

The majority of the materials relate to Palmer's work as a commissary general during the Cayuse War, as superintendent of Indian Affairs for the Oregon Territory in the 1850s, and as an Indian agent on the Siletz reservation in the 1870s. These papers consist of correspondence; reports, copies, and drafts of treaties with Native peoples; reports; financial disbursements; diary entries; and a later history of the Grande Ronde Military Block House that quotes Palmer's regulations. Many letters are to or from George W. Manypenny; other correspondents include Jesse Applegate, Benjamin Bonneville, George L. Curry, Berryman Jennings, Joseph Lane, R. B. Metcalfe, Nathan Olney, J. L. Parrish, W. W. Raymond, R. R. Thompson, and John Ellis Wool.

Other papers of Joel Palmer in the collection include a diary he kept while traveling from Oregon to Washington, D.C. in 1857; materials relating to his tenure as major general of the Oregon Militia during the U.S. Civil War and to his involvement with the Union League; property and financial records; typescript copies of correspondence and diary entries; a letter from U.S. Senator John H. Mitchell; and a microfilm copy of a day book for a general store in Champoeg, Oregon, that also includes business records of Palmer and his family.

Family papers in the collection primarily consist of correspondence of Palmer's wife, Sarah Ann Palmer, and of his descendants, but also include two poems from the late 18th century and a letter fragment from approximately 1800.