This collection is composed primarily of research files compiled for Hansen's study of federal-state relations in the Central Valley, which resulted in his dissertation, The Central Valley Project: Federal or State?(also published by the California State Assembly Interim Committee on Conservation, Planning and Public Works as Volume 13, no. 6, of the Committee's reports). Includes extensive interview notes, correspondence, reports, and detailed annotations of sources consulted.

Also includes materials on electric power rates (compiled by Hansen as an economist at the Office of Price Stabilizationfor submission to the California Public Utilities Commissionin the "PG & E rate case" of 1951), the irrigation districts movement in California, and the 1960 Census of Irrigation.