Skip to Content
Project_8_Main_Project_image.jpg
Ancient irrigated field systems and an agricultural settlement in the northern Tucson Basin

Ancient irrigated field systems and an agricultural settlement in the northern Tucson Basin

Prior to the expansion of Pima County’s Tres Rios Wastewater Reclamation Facility, Desert Archaeology investigated an Early Agricultural period irrigation community, where farmers lived and grew maize for several centuries from 1200 B.C. to 800 B.C. The project documented a sequential network of canals and hundreds of small bordered fields that they watered, along with associated field houses and living areas. The oldest deposits were found nearly 3 meters below the modern ground surface, buried along with their younger counterparts by sediments left by countless floods over the past three millennia. In 2009, Archaeology Magazine chose the Las Capas project as one of the ten most important discoveries world-wide. In 2015, Desert Archaeology was recognized by the Shanghai Archaeology Forum for over a decade of research on the Early Agricultural period that culminated in the Las Capas project.

Date:
June 2015
Location:
Marana, Pima County, Arizona
Type:
Data Recovery
Compliance:
Local
Client:
Pima County
DAI Reports:
Anthropological Papers Nos. 50 and 51; Technical Report Nos. 2012-016, 2014-01, 2014-02, 2014-08, 2014-09, 2014-10
Services:
Data Recovery
Archaeological Reconstructions
A small cluster of San Pedro phase houses during excavation.
The Las Capas site contains the earliest agricultural fields yet discovered in North America. Our crew re-created a maize garden within an ancient field, using tools and technologies similar to those used 3,000 years ago. The main difference is that we used a hose, rather than the now-dry Santa Cruz River, to fill the canal.
Reconstruction of Las Capas, by Rob Ciaccio.
Phytoliths (preserved mineral linings of plant cells) from Las Capas: (a, b) maize; (c) bottle gourd; (d) cucurbita; (e) freshwater sponge, indicating a perennial flow in the Santa Cruz River; (f) modern Tohono O’odham bottle gourd reference (Photomicrographs by Chad L. Yost, University of Arizona).
The dark ash- and charcoal-stained sediment fire-cracked rock from a cleaned-out roasting pit show the shape of this San Pedro phase canal, and then subsequent layers of filling.
Quick Findings
10+
Years of research on the period