Archaeology at Alkali Ruin

Author(s): Kris Dobschuetz

Year: 2003


Arizona Public Service (APS) and Salt River Project (SRP) were issued a Certificate of Environmental Compatibility (CEC) by the Arizona Corporation Commission (ACC) for the construction of the Southwest Valley 500kV Transmission Line Project (Southwest Valley Project). The project consists of 37 miles of 500 kilovolt (kV) transmission line to interconnect electric generation resources in the west valley with the existing 230kV system in the metropolitan Phoenix area. The project is located in Maricopa County.

In compliance with the Arizona State Historic Preservation Act, the ACC included several stipulations in the CEC concerning the further treatment and protection of those cultural resources crossed by the project. Previous intensive pedestrian survey of the project’s area of potential effect (APE) identified eight sites eligible for listing on the National Register of Historic Places (NRHP) (Dobschuetz and Darrington 2001; Hackbarth 2001). All but one of these sites, Alkali Ruin AZ T: 11:24 (ASM), were avoidable through spanning and monitoring. In consultation with the Arizona State Historic Preservation Office (SHPO), a treatment and work plan was developed to mitigate the impacts that would be caused by construction of the Southwest Valley Project (Dobschuetz et al. 2002). This report documents the final results of the archaeological investigations conducted at Alkali Ruin.

Archaeological investigations at Alkali Ruin commenced on September 17, 2002 and terminated on November 1, 2002 under Arizona State Museum (ASM) Project Specific Permit No. 2002- 109ps. A total of 103 person days were required to complete the fieldwork. Dr. Glenn Darrington served at principal investigator and senior reviewer; Matt Hill and Kris Dobschuetz served as co-field directors; Regina Chapin-Pyritz and Kris Dobschuetz served as co-laboratory directors; with field crew Kim Kennedy, Glennda Luhnow, and Sharon Bauer. Bruce Phillips of Archaeological Consultants served as project geomorphologist.

Fieldwork included three phases of investigation: (1) surface investigation, (2) subsurface testing, and (3) data recovery. Surface investigation identified three artifact concentrations and reexamined the historic Old Buckeye Canal alignment. A total of 15 features were identified during the testing phase, of which seven were selected for further study through data recovery. These included three canal segments (Features 2, 8a, and 15), three thermal features (Features 3, 4, and 10), and a pit structure (Feature 1). Laboratory analysis began November 8, 2002 and continued through August 1, 2003.

Although the archaeological investigation of Alkali Ruin has improved our understanding of the prehistoric use of this segment of the Gila River, the level of prior disturbance encountered during the excavation significantly limited the research potential of those few intact features that were identified. Previous development of historic canals and utility lines in the area coupled with the episodic flooding of the Gila River over many decades have degraded the depositional context. Given this situation, however, it was still possible to gather some information that has added to our knowledge of Alkali Ruin, including its chronology, prehistoric land use, and the use of wild and domesticated resources.

Based upon data identified during the testing and data recovery at Alkali Ruin in addition to previous research at the site, it appears that the site had been revisited numerous times from the late Archaic Period through the Classic Period. Although information about the prehistoric land use is somewhat limited, it suggests that different portions of the site were used differently. For example, certain areas contain artifacts that suggest resource procurement areas while other areas support evidence for small-scale agricultural activities. The density and diversity of ceramic types and the presence of exotic items suggest that a portion of the site may have also been used as a habitation area; however, no evidence of formal pit houses was identified within the areas of investigation. Lithic analysis did provide some interesting insights into the raw material procurement identified at the site. Locally available river cobbles were used in the production of the majority of lithic debitage and formal tools.

In summary, the data recovery that was conducted at the Alkali Ruin has sufficiently mitigated any adverse effect the Southwest Valley Project may have had on the site.

Cite this Record

Archaeology at Alkali Ruin. Kris Dobschuetz. 2003 ( tDAR id: 427181) ; doi:10.6067/XCV8427181

This Resource is Part of the Following Collections

Temporal Coverage

Calendar Date: 410 to 680 (Date range for Feature 1, AMS date)

Calendar Date: 450 to 670 (Date range for Feature 1, AMS date)

Calendar Date: 480 to 520 (Date range for Feature 1, AMS date)

Spatial Coverage

min long: -112.413; min lat: 33.391 ; max long: -112.367; max lat: 33.407 ;

File Information

  Name Size Creation Date Date Uploaded Access
2003_Dobschuetz_ArchaeologyAlkali_OCR_PDFA.pdf 121.24mb Feb 6, 2017 Mar 9, 2017 12:22:01 PM Confidential
This file is unredacted.

Accessing Restricted Files

At least one of the files for this resource is restricted from public view. For more information regarding access to these files, please reference the contact information below

Contact(s): Salt River Project Cultural Resource Manager