Esta última hipótesis es atractiva debido en parte a un estudio seminal de paleodemografía y la salud en el lugar de Período Clásico de Pueblo Grande en la cuenca de Phoenix. Explicaciones propuestas incluyen la migración, la dispersión de la poblacion en los asentamientos arqueológicamente menos visibles y disminución de la población mayor. Los principales centros de población ya no estaban ocupadas y muchos de los rasgos culturales distintivos materiales asociados con la tradicion Hohokam parecen desaparecer. La evidencia arqueológica documenta una aparente despoblación de la región Hohokam del sur de Arizona a finales del período clásico (1150-1450 d.C). Birth rates are sensitive to cultural and economic forces, and we should look beyond health factors in trying to account for the disappearance of Hohokam traditions. Population decline at the end of the Classic period is more likely explained by reduced fertility than by increased mortality. A hazards analysis of the published demographic data reveals life expectancy at birth in the expected range for prehistoric populations with no evidence of a dependency crisis. That study suggested that the population was not sustainable due to very low life expectancy, a very high dependency ratio of juveniles to adults, and other indicators of biological stress. The latter hypothesis is attractive partly because of a seminal study of paleodemography and health at the Classic-period site of Pueblo Grande in the Phoenix Basin. Proposed explanations include migration, dispersion of the population into less archaeologically visible settlements, and wholesale population decline. Major population centers were no longer occupied, and many distinctive material culture traits associated with the Hohokam tradition seem to disappear. It is suggested that this term be confined to the culture pattern which developed in the Gila Valley and thus to separate the Hohokam from those Amargosans who developed in the Sonoran Brownware tradition, who might be called the 'Ootam.Archaeological evidence documents apparent depopulation of the Hohokam region of Southern Arizona at the end of the Classic period (A.D. A redefinition of the term 'Hohokam' is proposed. Yuman entry into the South-west is thought to be late, opposing Schroeder's Hakatayan theory. Descendants of captive Hohokam survive as the Buzzard and Red Ant moieties of the Papago and Pima.

At that time, Piman-speaking Sobaipuri from the east, belonging to the Sonoran Brownware tradition, invaded the Hohokam territory and conquered it. 1400, with varying rates of accretions of traits and immigrants from the homeland.

There the culture developed and expanded until A.D. Given the corridor of Piman speakers from south to north, a group of these southern people is thought to have brought the Vahki phase of the Hohokam, en bloc, to Snaketown on the Gila River, about 300 B.C. At the extreme southern end of the range, Amargosans were in contact with Mesoamerican culture, and they acquired pottery making, canal irrigation, and other specialized traits from this contact. It is proposed that the Amargosans spoke an ancestral Piman tongue and that the present range of Piman speakers, from the Gila River to the Río Santiago in Jalisco, represents the extent of the Amargosan occupation. The present weight of evidence indicates that the Sierra Pinacate, Sonora, was an enclave occupied continuously from the end of the Altithermal period by people of the Amargosa complex, who, as Areneños, spoke a dialect of Papago in historic times.

Hohokam political structure