Quality of water in Colorado River in 1925-1926

Most of the analyses given in this report represent composites of daily samples collected by the observers at United States Geological Survey gaging stations on Colorado River at Grand Canyon and Topock, Ariz. These stations are operated under the direction of W. E. Dickinson, district engineer of the Geological Survey at Tucson, Ariz., who personally collected some of the samples at other points and arranged for the collection of others.