Chupadero Arroyo

William Doleman and Janette Elyea, University of New Mexico Office of Contract Archaeology (OCA)

In 1999, we tested several archaeological sites in the path of a central New Mexico road improvement project in an area overlooking the Trinity site, the scene of the first atomic bomb test in 1945. Three of the tested sites—together with nearby Mockingbird Gap site—are part of a concentration of Paleoindian and Archaic sites along Chupadera Arroyo in the northern Jornada del Muerto Basin.

The basin lies east of the Rio Grande Valley, and the northern basin’s main drainage is the intermittent Chupadera Arroyo. The landscape is characterized by eolian (wind-deposited) sand overlying eroded late Pleistocene fluvial (stream-deposited) and eolian sediments. There is evidence that the arroyo flowed mostly year-round during the terminal Pleistocene and early Holocene occupations, and it is likely that a riparian vegetation zone was surrounded by a lush grassland. The cluster of sites lies between 4,900 and 5,200 feet above sea level.

Mockingbird Gap, a 35-acre site that was first surface-collected and tested in the late 1960s by Robert H. Weber (New Mexico Bureau of Mines and Mineral Resources) and George A. Agogino (Eastern New Mexico University), was occupied by Clovis, Folsom, Cody, and Archaic groups. The Clovis occupation was a large, recurrently occupied campsite, as reflected by the more than 150 Clovis points and unfinished points, knives, gravers, endscrapers, sidescrapers, utilized flakes, bifacial and multi-sided cores, and manufacturing debris that have been recovered from Clovis contexts.

Several aspects of the artifact assemblages from the recently tested sites indicate Paleoindian and Archaic occupations: bifaces and biface manufacturing debris of a wide variety of non-local materials, including obsidian and chert from the Chuska Mountains 400 kilometers to the northwest; fragments of a fluted point and a large hafted biface; several flakes with parallel dorsal flake scars characteristic of Plano and Cody lithic technology; and ground stone tools and fire-cracked rocks typical of Archaic sites in the region. These types of artifacts accord with geological evidence for the ages of the new sites.

Most of the artifacts were from the middle of a sequence of three eolian deposits with truncated soil horizons overlying gypsum- and carbonate-enriched late Pleistocene eolian and fluvial sediments—but Clovis artifacts were also found in the lowest part of the eolian sequence at the Mockingbird Gap site. Although the uppermost eolian unit dates to the historic period, the lower two eolian units exhibit carbonate development suggesting ages of less than 9,000 years and ca. 15,000–8,000 years. This sequence is similar to that at the Mockingbird Gap site, from which Weber infers that a climatic shift toward increasing dryness in the terminal Pleistocene accelerated during the early Holocene, with a small perennial stream during Clovis time becoming an intermittent wash during the later Paleoindian occupations.

The Paleoindian and Archaic sites, extending three and a half miles along Chupadera Arroyo, are clearly an important resource for learning more about the earliest peoples of the Southwest. Upcoming excavations at the three recently tested sites will focus on exposing possible occupation surfaces, recovering datable materials, refining the geological sequence, and comparing paleoenvironmental evidence with regional data.

For more information on the Mockingbird Gap site and other Paleoindian sites along Chupadera Arroyo, see:

Elyea, Janette M., and William H. Doleman
2000 Test Excavation Results and Data Recovery Plan for Eight Prehistoric Archaeological Sites along Highway U.S. 380 East of San Antonio, New Mexico. OCA/UNM Report No. 185-655C. Office of Contract Archaeology, University of New Mexico, Albuquerque.

Weber, Robert H.
1997 Geology of Mockingbird Gap Site in Central New Mexico. In Layers of Time: Papers in Honor of Robert H. Weber, edited by Meliha S. Duran and David T. Kirkpatrick, pp. 115–122. Archaeological Society of New Mexico, Albuquerque.

Weber, Robert H., and George A. Agogino
1997 Mockingbird Gap Paleo-Indian Site: Excavations in 1967. In Layers of Time: Papers in Honor of Robert H. Weber, edited by Meliha S. Duran and David T. Kirkpatrick, pp. 123–127. Archaeological Society of New Mexico, Albuquerque.