The Tres Alamos Site on the San Pedro River, Southeastern Arizona

Author(s): Carr Tuthill

Year: 1947


The ruins lie on the east bank of the San Pedro River some twelve miles by road north of the town of Benson. At this point the river has started to cut into an erosion terrace or bench on which the ruins are located. This bench rises about one hundred to one hundred and fifty feet above the bed of the river, and is eroded by relatively short but deep and steep-banked gullies or arroyos into several tongues of land fanning out toward the river. Evidences of prehistoric occupation are found on the terrace and its tongues of land.

The land on the west bank of the river lies considerably lower than that on the east bank, and is formed by the low-lying flood plain or river bottom land about twenty to thirty feet above the bed of the river, which has cut a deep and vertical-banked channel within the last fifty or sixty years. Historical records show that in the 1870’s and ’80’s the San Pedro River was a perennial live stream that had not yet cut its present deep channel.

The low-lying land making up the flood plain is very fertile as evidenced by modern farming carried on there, and was undoubtedly used in prehistoric times for agricultural purposes. Sherds were found on the flood plain immediately across from Tres Alamos but there were no evidences of dwellings. This is not too surprising in view of the fact that this land floods badly during the heavy summer rains.

No traces of prehistoric irrigation ditches were found, although a canal dug in the late 1800’s, that might have followed an earlier one, was discovered. It is known that this was sometimes the case in the Salt River Valley of Arizona. Lack of evidence of prehistoric canals does not necessarily imply that they were nonexistent. The principles of crop irrigation by canals was well known in the southwest at the time that Tres Alamos was inhabited, and the basis of the economy at that time was agriculture. Erosion has been quite severe in the San Pedro Valley and all traces of prehistoric water systems may have long since disappeared.

Cite this Record

The Tres Alamos Site on the San Pedro River, Southeastern Arizona. Carr Tuthill. No. ,4. Dragoon, Arizona: The Amerind Foundation, Inc. 1947 ( tDAR id: 448860) ; doi:10.48512/XCV8448860

This Resource is Part of the Following Collections

Spatial Coverage

min long: -110.429; min lat: 31.331 ; max long: -109.056; max lat: 32.246 ;

Individual & Institutional Roles

Contact(s): Amerind Museum

Contributor(s): W.S. Fulton; E.W. Haury; L.L. Hargrave; Hildegard Howard

Principal Investigator(s): Carr Tuthill

Repository(s): The Amerind Foundation, Inc.

Prepared By(s): The Amerind Foundation, Inc.

File Information

  Name Size Creation Date Date Uploaded Access
1947_Tuthill_TresAlamosSite_Redacted.pdf 54.32mb Apr 20, 2021 8:58:39 AM Public
This file is the redacted version of the resource.
1947_Tuthill_TresAlamosSite_OCR_PDFA.pdf 44.42mb May 21, 2019 3:39:04 PM Confidential
This file is the unredacted version of the resource.

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): Amerind Museum

This Resource is Part of the Following User Created Collections