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Agriculture, 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 five major series, which were further broken down into various types and phases. A large percentage of the soils adjacent to the Gila River channel were not differentiated as to series; rather they were grouped into alluvial soils. The soils placed in the five series were considered to be well adapted to general farming, except for minor local areas of shallow soil. The 1929 report also contains a map which portrays the salinity conditions of the valley at the time of the survey. The map shows that most of the lands have a slight to moderate saline condition, with numerous areas being strongly affected. In the spring of 1941, the Bureau of Reclamation initiated a semidetailed land classification of the Wellton-Mohawk Division of the Gila Project. In this classification, Classes 1, 2, and 6, as designated by Bureau standards, were mapped. However, in some cases, Classes 1 or 2 were further designated subject to periodic flooding 1/ Soil Survey of the Yuma-Wellton area, Arizona-California, United States Department of Agriculture, Bureau of Chemistry and Soils, in cooperation with the University of Arizona Agriculture Experiment Station - Series 1929 - Number 20. 56Epson Perfection 4870 Photo, 400 dpi, 8 bi