xxviii, 463 p. : ill., maps. A print copy of this title is available through the UO Libraries under the call number: KNIGHT F868.M65 J45 1991 / The environmental context and chronology of the transition from Early Holocene Lake Mojave to Middle Holocene Pinto cultural complexes of the southern California deserts has long been debated. This dissertation re-examines that debate, based on excavations at two major sites, and a rethinking of our most basic assumptions concerning culture change, cultural ecology, site formation processes, and dating techniques. Archaeological data recovered from two Lake Mojave/Pinto sites at Fort Irwin, in the Central Mojave Desert, were analyzed in order to track chronologically sensitive shifts in Lake Mojave-Pinto artifact assemblages through time. The archaeological assemblages recovered from Rogers Ridge and the Henwood sites were carefully analyzed into 36 depositional/analytical components for this task. Defining and chronologically ordering these assemblages required systematic consideration of artifact distributions and the development and application of 3 obsidian hydration rates based on associations with twelve 14C dates. The analysis shows that the Pinto Complex occurred in three phases. Phase I, ca. 8,200 to 7,500 BP, is marked by the addition of Pinto points to the Lake Mojave assemblage and a continuation of the basic Lake Mojave settlementsubsistence patterns. Phase II, 7,500 to 5,000 BP, is marked by the gradual disappearance of Lake Mojave points from the archaeological assemblages. Dramatic decreases in assemblage size and increases in assemblage diversity mark changing logistical strategies to infrequent and specialized site use. Phase III, 5,000 to 4,000 BP, is marked by a strong predominance of Pinto points and slightly larger assemblages. Patterns of variation among assemblages suggest that logistical strategies continued to emphasize infrequent and specialized site useage. The link between environmental change and shifting settlement-subsistence strategies was apparently relatively direct during the Pinto period, Environmental changes during the Early Holocene (11,000 to 8,000 BP) Mojave Desert led to subsistence stress among populations of the Pinto Complex. Cultural adjustments resulted in smaller human populations moving through larger home territories. It is suggested that critical thresholds in communication and mating networks were crossed which resulted in the collapse of social systems in the Mojave Desert about 7,000 BP. / Committee in charge: C. Melvin Aikens, Ann Simonds, Don E. Dumond, and William Loy