PHYSICAL AND SOCIAL LANDSCAPES
LATE PREHISTORIC MOUND CENTERS
NORTHERN CADDO AREA
A dissertation submitted in partial fulfillment
| This dissertation
is a study of late prehistoric mounds constructed in the Northern Caddo
Area of northwestern Arkansas, northeastern Oklahoma, and southwestern Missouri.
The study concentrates on the relationship of the mounds to the landscape
- how they are situated in relation to arable bottomland, and from how large
of an area on the landscape the mounds were visible. Both of these factors
have implications for the environmental adaptations and social structures
of the people who built the mounds.
You can read the full abstract of the dissertation below (click here).
The entire dissertation is available below in PDF format, in 11 separate
sections. Be aware that some of the files are fairly large. To download
them directly to your computer, right-click on the highlighted link and
select "save as".
DEM of the study area. Click image for larger version.
A Few Points of Interest:
Several of the mound sites are currently under the water of artificial
reservoirs, and available digital elevation model (DEM) datasets show
the elevation of the modern water level. To reconstruct a closer approximation
of the prehistoric landscape, I digitized numerous early paper maps of
river topography, and incorporated these elevations into the DEMs. I reconstructed
the pre-reservoir topography of Eufala Lake, Robert S. Kerr Lake, Fort
Gibson Lake, and Grand Lake O' the Cherokees in this way. While far from
perfect, these reconstructed topographic models served very well for the
purposes of this dissertation, and may be of use to other researchers
as well. Information about the generation of these DEMs can be found in
Chapter 5. You can download the DEMs of reconstructed
reservoirs for you own use here.
This dissertation involved a large-scale viewshed analysis employing Monte-Carlo modeling to determine the statistical background for viewsheds within different topographic regions of the study area. Details concerning these procedures is found in Chapter 6.
I also conducted elaborate proximity analysis to determine how much arable
bottomland was available to the mound sites. This type of study is often
referred to as 'catchment analysis', and may be conducted several different
ways. I conducted the study using four different theoretical assumptions
about travel across a landscape:
I made extensive use of early aerial photographs (from the 1930s to 1950s)
in this study, to great effect. These aerial photographs were generally
taken when much of the bottomland (where the mound sites are) was cleared
of vegetation for farming, but before the reservoirs were constructed
and before much large-scale landscape modification or urban development.
These photographs helped me reconstruct some of the early landscape, locate
some of the mounds that are gone now (and whose precise location was unknown),
and to interpret prehistoric landscape modifications around some of the
mound centers (I use the aerial photographs extensively in the site descriptions:
The overall conclusions I drew from this study are:
1) Many of the mound sites are situated preferentially on the landscape with regard to viewsheds. Mound sites in the Arkansas and Neosho River valleys, particularly the larger sites, are situated in locations with viewsheds far larger than would be expected by chance alone. Mound sites in the Ozark uplands, on the other hand, appear to be situated in locations with preferentially small viewsheds.
2) The size and elaboration of sites in the Arkansas and Neosho River valleys corresponds fairly well with the amount of locally available arable bottomland. In other words, larger sites are situated near larger tracts of good farmland. This is fairly intuitive, and holds true no matter which of the theoretical assumptions about travel across a landscape (explained above) is used. Sites in the Ozark uplands, however, do not express this pattern. In this region, the mounds are all situated along streams, but the amount of locally available bottomland does not seem to be an influence on the size or elaboration of the sites.
3) Both the viewshed and bottomland proximity analyses suggest that there are quite different meanings or uses of the mound sites between the major river valleys and the uplands. Prehistoric people in these areas were certainly in communication with one another and part of an overall integrated regional system, but there appear to be significantly different cultural practices and processes between the regions.
4) While a large amount of bottomland in close proximity appears to be necessary for sustaining large sites in the large river valleys, the bottomland alone was not sufficient for founding or sustaining a large center. Large tracts of bottomland exist along the Arkansas and Neosho Rivers within which there are no large mound centers. In other words, large amounts of bottomland resources may have created the potential for the development of large mound centers, but this potential was not realized in some locations.
Please note that these are somewhat simplified versions of the overall conclusions from the dissertation. You can read the rest of the details in Chapter 8.
This dissertation is a study of late prehistoric mound centers in the northern Caddo area of northwest Arkansas, eastern Oklahoma, and southwest Missouri, concentrating on the relationship of the mounds to the natural landscape through viewshed and bottomland proximity analyses. The mounds are interpreted from published accounts, archival sources, early aerial photographs, and fieldwork. The regional landscape is modeled in Geographic Information Systems (GIS) as a digital elevation model (DEM), modified to more accurately reflect topography prior to river impoundment and other historic landscape alterations.
Monte Carlo statistical methods show that the mounds are located preferentially with respect to viewsheds. Mounds in the Arkansas and Neosho River valleys and Ouachita Mountains are situated in locations with statistically large viewsheds, and at least some in the Ozark Plateaus are situated in locations with statistically small viewsheds.
The mounds are also located preferentially with respect to alluvial bottomland. Alluvial bottomland within the study area was delineated with a novel GIS procedure, and the amount of bottomland near each mound site was determined through four models of proximity: straight-line distances, a simple friction-based cost surface model, a cost surface model considering rivers to be barriers to travel, and a cost surface model considering rivers to be corridors of easy travel. In general, the size and elaboration of mound centers corresponds to proximate bottomland. The correspondence is regional and follows a trend of increasing mound-center size downstream, correlating with increasing access to alluvial bottomlands.
Together, the viewshed and bottomland proximity results suggest different
cultural adaptations in the uplands from those in the larger river valleys.
The amount of proximate bottomland has a greater influence on mound centers
in the river valleys than in the uplands, and while large tracts of bottomland
may have been necessary for large mound centers, this alone was not a
sufficient criterion for their development.
Introduction and Statement of Research Questions
| The study area
|The Natural Background|
|The "Northern Caddo Area"
A typology of mounds in the Arkansas Basin
Civic ceremonial centers
Social organization and mounds
|Building the GIS Model|
|Bottomland Proximity Analysis|
Four models of proximity
Determining bottomland areas
Results of bottomland proximity analysis
|Summary and Conclusions|
|Aerial photograph interpretations
Site descriptions: Arkansas sites
Site descriptions: Missouri sites
Site descriptions: Oklahoma sites
Other possible mounds
Non-mound site descriptions
B: Aerial Photograph Tables
Appendix C: GIS Procedures
Appendix D: Bottomland Proximity Tables
Appendix E: Nearest-Neighbor Analysis and Proximity Models
Appendix F: Contents of the DVD
Much of the archival work for this project was made possible by a grant from the National Science Foundation (DDI Grant 0341068: Location and Patterning of Mississippian Mounds in the Central Arkansas River Valley), and a Dissertation Research Travel Grant from the University of Arkansas.
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