One of the first requisites for intelligent planning of the utilization and control of water and for the administration of laws relating to its use, is data on the quantity, quality, and mode of occurence of water supplies. The collections, evaluation, interpretation, and publication of such data constitute the primary function of the Water Resources Division of the United States Geological Survey. Since 1895 the Congress has made appropriations to this agency for investigations of the water resources of the Nation. In 1929 the Congress adopted the policy of dollar-for-dollar cooperation with State and local governmental agencies for water-resources investigations. The Geological Survey's Federal-State cooperative program of quality-of-water investigations in Oklahoma was started in 1944 in cooperation with the Oklahoma Planning and Resources Board. Since July of this year the program has been carried on cooperatively with the newly created Oklahoma Water Resources Board.