Materials in this collection were compiled by Barbara Mackenzie (frequently identified as Mrs. T. T. Mackenzie), who directed the Celilo Falls relocation project. The records date primarily from 1954-1957, and document official activities associated with the process of removal and relocation of Native residents. The records consist of correspondence, minutes of advisory committee meetings, relocation plans, and case files for affected residents. These case files contain applications, summaries of action taken, and photographs of housing before and after relocation. Many of the documents deal with the residence status of individuals and families at Celilo, as well as their specific plans and preferences for relocation. Other records relate to Native burial relocation, monetary amounts provided, and a breakdown of Celilo residents by tribe.

The records were produced by individuals and representatives of various organizations and government offices, including the Bureau of Indian Affairs and its agencies for the Umatilla, Warm Springs, and Yakama tribes; the Wasco County court; the Army Corps of Engineers; and the Klickitat County Welfare Department, among others.