Frank L. Cowan

Cowan and Associates

Ted S. Sunderhaus

Cincinnati Museum Center
Ohio Archaeological Council © 2002

The relatively short time-span of Ohio Hopewell, coupled with the extraordinary abundance of large, labor-intensive earthwork complexes throughout southern Ohio, raises important questions about the contemporaneity and duration of use of individual earthwork complexes and about the population densities and dynamics necessary to build and use them. Such questions can be addressed with reasonable precision only with much stronger controls over the age and use-life of individual sites. The Stubbs Earthworks complex (Figure 1) in Warren County, Ohio (Cowan, et al. 1998, 1999; Genheimer 1996, 1997; Sunderhaus, et al. 2001) offers a unique opportunity to address the age and duration of use of a Hopewell earthwork complex. Thus far, we have obtained 18 radiocarbon dates from several associated wooden structures of markedly varied architectural forms (Table 1).

Table 1. Radiocarbon Dates for Wooden Structures at the Stubbs Earthworks Site (33Wa1).
Number and
Radiocarbon Age BP
(corrected for C12/C13 ratio)
Weighted Average BC/AD
2 119 Beta-156234 1640 +/- 60
2 150 Beta-156235 1890 +/- 70
2 158 Beta-156236 1550 +/- 60
Structure 2 (circular) Average does not include F. 150 date AD 355 +/- 42
4 191 Beta-156237 1770 +/- 60
4 223 Beta-156238 1850 +/- 70
4 376 Beta-156239 1850 +/- 70
Structure 4 (rectangular)
AD 133 +/- 38
5 256 Beta-156240 1820 +/- 70
5 294 Beta-156241 1800 +/- 60
5 332 Beta-156527 1810 +/- 70
Structure 5 (square)
AD 142 +/- 38
6 142 Beta-156528 1890 +/- 60
6 321 Beta-156526 1730 +/- 60
Structure 6 (C-shaped)
AD 140 +/- 42
8 531 Beta-156230 1770 +/- 70
8 537 Beta-156231 20 +/- 50
8 594 Beta-156232 1790 +/- 70
8 632 Beta-156233 1750 +/- 60
Structure 8 (Great Circle) Average does not include modern F. 537 date AD 180 +/- 40
11 770 Beta-156529 2930 +/- 50
11 826 Beta-156530 2790 +/- 60
Structure 11 (circular)
922 +/- 38 BC
Pit intruding into
Structures 19 and 21
(wall-trench structures)
951 Beta-156531 1920 +/- 60 AD 30 +/- 60

Most of the excavated structures lay outside the earthwork enclosure and relate only by inference to the earthworks themselves, necessitating a chronological anchor for the earthworks proper. The only presently dated earthwork feature is the detached circular embankment located south of the major enclosure. In the location where Whittlesey (1851) mapped a large circular earthen enclosure (Figure 1), we encountered Structure 8, a 73-meter-diameter circle of 172 very large post holes, each capable of supporting a moderate-sized telephone pole (Figure 2).

Figure 1: Stubbs Earthworks and 1998-1999 Project Area.
Figure 1: Stubbs Earthworks and 1998-1999 Project Area.


Charcoal from the sediments used to refill four post holes are now dated. One post hole yielded a modern date, indicating we missed a recent intrusion into that feature. However, three post mold fills yielded nearly identical radiocarbon age estimates with a weighted average of AD 180 +/- 40. This is the single best estimate for the age of this monumental structure, indicating that the large post circle and the subsequent earthen embankment dates to about the latter half of the second-century AD.

Figure 2: The 'Great Post Circle.' Labeled features are radiocarbon dated.
Figure 2: The 'Great Post Circle.' Labeled features are radiocarbon dated.


About 60 meters east of the main rectangular embankment, excavations revealed at least five house-sized wooden structures (Figure 3). Two structures are square to rectangular in form, one structure is C-shaped, and two structures are circular. Three dates from the rectanguloid Structure 4 provided a weighted average of AD 133 +/- 38. Three post molds from Structure 5, the larger square building, resulted in a weighted average of AD 142 +/- 38. The small C-shaped structure, probably representing a half-domed shelter, was built and used about AD 140 +/- 42. All three wooden structures are essentially contemporary within the levels of precision afforded by radiocarbon dating. Structure 3, a double-posted circular structure, awaits AMS dating, but mica scraps and an incised Hopewell series bowl sherd in several post molds substantiate its Hopewellian age. Structure 2 is a large circular structure with a central post and an interior partition. Of the three radiocarbon dates, one is much older than the others, suggesting that midden sediments used to refill that post hole contained charcoal from previous Hopewellian uses of the area. Two dates, however, are consistent, and AD 355 +/- 42, the average of the two younger samples, is the single best estimate of the actual age of the structure.

Figure 3. Structures 2 - 6 in Transect 10. Labeled features are radiocarbon dated.
Figure 3. Structures 2 - 6 in Transect 10. Labeled features are radiocarbon dated.


Eight (possibly eleven) house-sized, house-like structures in Transect 27 (Figure 4), some 300 meters south of the major earthwork, are especially intriguing in that they were built using the wall-trench construction technique. Dating these wall-trench structures must await AMS dating, but we already have one informative radiocarbon age estimate from this transect. Feature 951 is a small, charcoal-rich pit that intruded into two overlapping wall-trench structures and necessarily postdated both Structures 19 and 21. The date for Feature 951 is AD 30 +/- 60. While determining the ages of the several structures in this transect will require many AMS dates, the available date confirms that wall-trench construction was not a Mississippian innovation and suggests that wall-trench construction techniques may have been in use quite early in the Hopewellian period.

Figure 4. Transect 27 Wall-Trench Structures. The labeled feature is radiocarbon dated.
Figure 4. Transect 27 Wall-Trench Structures. The labeled feature is radiocarbon dated.


Lastly, we turn to wooden structures we originally thought to be Hopewellian but which yielded dates much earlier than anticipated. Structures 11 and 13 were circular buildings 10-meters in diameter, one replacing the other in the same location (Figure 5). The western margins of those structures were eroded away along the terrace edge. Thus far, we have only two dated post molds from Structure 11 which yielded a weighted mean of 922 +/- 38 BC, indicating that this structure dates to the very early portion of the Early Woodland period. This unexpectedly early date, along with similar clues from Fort Ancient and other Ohio Hopewell earthwork complexes, suggests that many of these "special places" on the region's landscape were special places for very long periods of time.

Figure 5. Transect 26 Circular Structures. Labeled features are radiocarbon dated.
Figure 5. Transect 26 Circular Structures. Labeled features are radiocarbon dated.


In summary, Ohio Hopewell wooden architecture was highly diverse (contra Baby 1971), and there is now no reason to think that such variability was time-dependent (Figure 6). The Great Post Circle provides a late second-century to very early third-century chronological anchor for at least a portion of the earthworks. Rectangular structures, many or all built using the wall-trench construction technique, were in use throughout the first and second centuries. Half-dome structures, signified by C-shaped post mold patterns, were contemporary with rectangular structures. Circular post-built housing occurs as early as the earliest portion of the Early Woodland period and also near the close of the Middle Woodland period; there is no reason to think it was not also used throughout the intervening period. Temporal sources of variability now seem very unlikely, and we must turn our attention to other reasons for such architectural variability.

Figure 6.  Summary of Dates for Stubbs Earthworks Wooden Structures.
Figure 6. Summary of Dates for Stubbs Earthworks Wooden Structures.


Although the duration of actual mound-building and earthwork construction at the Stubbs Earthworks has not been demonstrated, the Hopewellian use of the site clearly extends from, at least, the first century AD through the fourth century AD. This relatively long period of use means that the Stubbs Earthworks was contemporary with the long-lived Fort Ancient earthworks, located only eight kilometers miles up the Little Miami River. It was probably also contemporary with other nearby earthwork complexes, such as Fosters Works, located about eight kilometers downstream. Given the close spatial proximity of these earthwork sites, it seems more than likely that individual local communities were building and using multiple ceremonial complexes at the same time.

References Cited

Baby, R. S.
 1971   Prehistoric Architecture: A Study of House Types in the Ohio Valley. Ohio Journal of Science 71(4):193-198.

Cowan, F. L., T. S. Sunderhaus and R. A. Genheimer
 1998  Notes from the Field: An Update from the Stubbs Earthworks Site. The Ohio Archaeological Council Newsletter 10(2):6-13.

 1999  Notes from the Field, 1999: More Hopewell "Houses" at the Stubbs Earthworks Site. The Ohio Archaeological Council Newsletter 11(2):11-16.

Genheimer, R. A.
 1996  Bladelets are Tools Too: The Predominance of Bladelets Among Formal Tools at Ohio Hopewell Sites. In A View from the Core: A Synthesis of Ohio Hopewell Archaeology, edited by P. J. Pacheco, pp. 92-107. The Ohio Archaeological Council, Inc., Columbus, Ohio.

 1997  Stubbs Cluster: Hopewellian Site Dynamics at a Forgotten Little Miami River Valley Settlement. In Ohio Hopewell Community Organization, edited by W. S. Dancey and P. J. Pacheco, pp. 283-309. Kent State University Press, Kent, Ohio.

Sunderhaus, T. S., R. Riggs, and F. L. Cowan
 2001  The Smith Site: A Small Hopewell Site Overlooking the Stubbs Earthworks. The Ohio Archaeological Council Newsletter 13(2):5-12.

Whittlesey, C.
 1851  Descriptions of Ancient Works in Ohio. Smithsonian Contributions to Knowledge 2, Smithsonian Institution, Washington, D. C.