Unfortunately, the development of the Salado can not be defined with a great degree of thoroughness. There simply has not been enough work with sites of the Salado Culture. However Gladwin did say:
Up to about 1300 A.D. Tonto Basin had been occupied by people of the Salado Branch who were making black-on-white pottery and building compounds which enclosed one-storey houses. At about 1300 A.D., groups of Kayenta people reached Tonto Basin, one-storey houses were changed to pueblos of several storeys, black-on-white pottery changed to polychrome in which features of both the Kayenta and Salado Branches were incorporated. (Gladwin 1937:103)
Haury was a bit more specific as to the roots of the Salado, by saying that the Salado apparently emerged from a fusion of Mogollon and Anasazi, the Anasazi elements being the more predominant (Haury 1945:205).
Discussion: On the basis of the above, very little may be said. But, be that as it may, some points are salient. The date of A.D. 1300 for the development of Gila Polychrome and the multi-story pueblos as proposed by Gladwin seems to be rather late. It is hard to believe that the Kayenta people moved into the Tonto Basin and at the same time the Salado were expanding to the South with a culture exhibiting traits of both Anasazi and Salado origin. It would require instantaneous fusion. Also, eight Hohokam sites have been found on the Salt Arm of Roosevelt Lake, dating from Colonial to Sedentary. No Classic sites were found. The sites contained Salado redwares and Gila Polychromes among other types (Ruppe 1966:9-10). The fact that these sites were located during a site survey and were not excavated, may indicate that the surface occurrences of Salado redwares and Gila Polychromes could possibly be fortuitous. This is to say that some good comprehensive field work could be used to help the cultural history of the Salado be defined.
The occurrence of the Hohokam sites in the Tonto Region (Haury 1932; Ruppe 1966) is interesting for two reasons. First, it indicates that the Salado were probably in contact with the Hohokam for some time before the advent of the Classic period. Secondly, the presence of sites of the Sedentary period but not of the succeeding Classic period indicates a Hohokam withdrawal. This withdrawal may not have been a purely local phenomena, as there is some evidence to indicate a withdrawal from up the Agua Fria River (refer to Appendix A) and the Verde River (Schroeder 1947:232) at about the same time.
Recent work by the Department of Anthropology, Arizona State University, at Walnut Creek near Young, Arizona, will probably throw a great deal of light on the Salado.