The objects of the joint investigations were to provide a general plan for the development and settlement of the Columbia Basin area as a whole, and detailed plans for areas to be irrigated. The topographic surveys and land classifications of the Bureau of Reclamation served as a base for the investigations. Twenty-eight separate problems, in addition to the basic engineering surveys, were set up for study. The problems were divided into 16 divisions. Lead investigators included Dr. E. N. Torbert, field coordinator for the joint investigators, Planning Consultant Harlan H. Barrows and Chief of Information William E. Warne, both representing the Bureau of Reclamation, and Marion Clawson of the Bureau of Agricultural Economics.

These materials contain miscellaneous published and unpublished reports on the Columbia Basin Project joint investigations. They were collected by Frank Adams, head of the University of California Division of Irrigation Investigations and Practice, who also served as a consulting engineer and economist to the Bureau of Reclamation.