Date of Award

Spring 4-1-2015

Document Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Stephen H. Lekson

Second Advisor

Catherine M. Cameron

Third Advisor

Darrell G. Creel

Fourth Advisor

Suzanne L. Eckert

Fifth Advisor

Arthur A. Joyce


In the Mimbres region of southwestern New Mexico, there are two notable periods of transition (around 1150 A.D. and again around 1300 A.D.) during the Postclassic Period. These periods are marked by dramatic changes in material culture, settlement reorganization, and population decline. The first represents the transition from the Classic Mimbres period (1000 to 1150 A.D.) to the Black Mountain phase (1150 to 1300 A.D.). The second represents the transition from the Black Mountain to the Cliff phase (1300 to 1450 A.D.). The scale (size of the population reorganizations), chronology (timing of the reorganizations), and nature (social processes behind the reorganizations) of these changes are not fully understood. Three processes have been proposed to account for the changes: depopulation followed by population replacement (immigration), population decrease with remaining groups changing material culture and reorganizing economic and social networks, or some combination of these scenarios. The Black Mountain site (LA 49), near Deming, NM, in the Lower Mimbres Valley, is the type site for the Black Mountain phase. It represents one of the largest Black Mountain phase settlements and also contains a large Cliff phase room block. Through field excavations and laboratory analyses, this dissertation explores whether the change in material culture represents cultural continuity or cultural change at the Black Mountain site. Multiple artifact classes (radiocarbon and dendrochronology data as well as ceramic and obsidian sourcing data) suggest the transitions represent both a continuation of resident groups and immigration of new populations. This dissertation also provides a comparison of Black Mountain phase data from other sites and provides evidence that the transition from the Classic to Postclassic periods was not a uniform process throughout the region.