United States Department of Interior, Stewart L. Udall, Secretary, Bureau of Reclamation, Floyd E. Dominy, Commissioner, Region 3, A.B.West, Regional Director, "Special Studies, Delivery of Water to Mexico", February, 1963, page 56Agriculture, Bureau of Soils, Field Operations. The Gila Valley lands eastward to the middle of Township 15 West and the mesa lands to the south of the Gila Valley to approximately the 350-foot contour were also covered by a soil survey conducted by the Department of Agriculture, Bureau of Chemistry and Soils, in cooperation with the University of Arizona, in 1929. 1/ In this survey, the soils of the Wellton-Mohawk valley were mapped according to series, types, and phases. The valley lands were segregated into fiv...