Uncovering Architecture Buried within a Caddo Mound

The mound originally stood at about 5.5 m (18´) high with a ramp on its northern side, but by 1971 was only 1.5 m (5´) high. With permission from the landowners and funding from the National Park Service, Weber and a small crew mapped the mound surface, established a grid, and excavated several profile trenches using a backhoe. Following that, they hand-excavated a series of 2 x 2 m (6.5´ x 6.5´) units in a block on the mound’s south side.

Just below the disturbed top zone, the archeologists discovered burned timbers and remnants of burned structures. They eventually identified portions of five mound surfaces or stages (designated Zero, First, Second, Third, and Fourth Mound). Three of the surfaces had residues of buildings that showed as circular patterns of posts or postholes (designated Zero Mound House, First Mound House, and Third Mound Houses 3A, 3A’, and 3B).

While structures were found at about the same depth on the west and east sides of the mound, Weber determined that they were not contemporaneous. The Third Mound Surface with its structures had been added on the west after the original mound had been built up on the east side with its Zero, First, and Second Mound surfaces and structures. The mound had originally been a two-level platform with a lower western side and a higher eastern side. Any Second or Third Mound structures that would have been on the higher east side had already been destroyed by mound leveling.

The buildings buried in the east side of Hays Mound had wall posts in circular patterns measuring 8 m and 10.7 m (26´and 35´) in diameter, with four larger interior posts set around central hearths. While separated by 60 cm (2´) of fill, the hearths and central posts of the Zero Mound and First Mound structures were nearly in the same locations. The First Mound structure was larger and had an extended entryway to the northwest. These structures had been burned and the walls collapsed inward, then covered with earth. On the west side of Hays Mound, three partial circular post patterns (10–14 m or 33–46´ in diameter, Third Mound House 3A, 3A’, and 3B) overlapped one another, with ash deposits and a central hearth/ash-filled post pit.

While the structures on the east side had been cleaned out before they were burned, the west side structures had abundant pottery sherds, stone tools, animal bone and mussel shells, and charred nutshell and seeds. To Cynthia Weber, the different treatments at the closure of the buildings indicated different functions; she concluded that the ancestral Caddo leaders’ residences stood on the lower western platform while public or ritual structures were placed on the higher platform on the east.

After fieldwork concluded, Weber completed the analyses and wrote a report. Unfortunately, it was not published or widely disseminated at that time. However, the Arkansas Archeological Survey has curated the artifacts, photographs, and records, ensuring that the project can be looked at again to generate new data and interpretations.

In 2018 and 2019, Ann Early (then Arkansas’s State Archeologist) re-inventoried and reanalyzed the Hays Mound artifacts. In 2023, Aswa Khan and Mary Beth Trubitt (the Arkansas Archeological Survey’s Henderson State University research station archeologist) input the field records and artifact inventory into the Survey’s customized FileMaker Pro program. A total of 4,908 artifacts and samples from Hays Mound have been entered and linked to the state’s Automated Management of Archeological Site Data in Arkansas (AMASDA) database.

These results suggest the time span between the earliest and latest constructions was even more compressed than indicated by the previous set of radiocarbon results. The construction and use of Hays Mound took place during the fourteenth century AD, probably over fewer than 100 years. Details of the architecture (the nearly identical placement of the central posts and hearth in the Zero Mound and First Mound structures) and from the pottery (the exclusive use of grog or grog and bone as temper, and the presence of East Incised sherds throughout the sequence) bolster this interpretation.

In the past, ancestors of the Caddo people constructed and used earthen mounds in numerous communities across what is now southwestern Arkansas. Many have been damaged or destroyed in the intervening centuries. Studying curated collections can provide new information without additional archeological excavation. This web page summarizes results of one such reanalysis project. The fourteenth-century architecture buried within the Hays Mound can be compared with that uncovered by excavations at other contemporaneous mound sites. In addition, these results can be used to visualize the community activities that took place at ancestral Caddo mounds that remain in Arkansas and encourage their continued preservation.

This project has been supported by grants from the Caddo Archaeology Research Fund and the Arkansas Archeological Survey’s Hester A. Davis Fund. The 1971 salvage excavations were directed by J. Cynthia Weber with a crew that included Burney McClurkan, Robert Taylor, Jeff Flenniken, Gene Hickman, Ellen Messer, Diane Taylor, Stephen Loring, Meeks Etchieson, Beverly Watkins, Beth Butler, Sam Watkins, Mike Yarborough, Floyd Ciganero, and Paul Schoen. The 2018–2024 reanalysis team included Ann Early, Mary Beth Trubitt, Aswa Khan, and Leslie Bush. Thank you to Caddo Nation Chairman Bobby Gonzalez and Tribal Historic Preservation Officer Jonathan Rohrer for permission and advice on this project. Project notes, records, photographs, and artifact collections (AMASDA Project No. 267) are curated at the Arkansas Archeological Survey’s Henderson State University Research Station in Arkadelphia.