The Double Ditch site, located in O'Brien County in northwest Iowa, was a small Native American agricultural village occupied around A.D. 1200. It is one of 31 other known villages that comprise the Mill Creek culture.
Map of Double Ditch and
Mill Creek sites.
Excavations were carried out at the site in 1994 and 2000, producing a variety of fascinating artifacts. These artifacts were then analyzed to answer some challenging questions about the length of time the site was occupied.
An aerial view of the site with the ditch and lodge depressions highlighted in red in image (b).
Right: native cultivation of corn
using a bison scapula hoe.
Above: a reconstructied Mill
Scholars disagree regarding how long villages like Double Ditch were occupied. Many archaeologists believe that they were continually occupied for hundreds of years while others claim that multiple lines of evidence reveal a much shorter occupation period.
By taking multiple measurementss of ceramic body and rim sherds, I used a mathematical equation to determine the percent of a pot that each sherd represents. Along with other data, such as the portion of the site excavated, this allowed me to make an estimation of the total number of pots discarded in the village during the time it was occupied.
Drawings of rim sherds and profiles from Double Ditch (by Matt Manning).
My research uses an in-depth ceramic analysis to conclude that the Double Ditch agricultural village (A.D. 1200) was occupied for less than one year.
A reconstructed lodge.
Combining the conclusion regarding number of pots present with evidence on population size and ceramic breakage rates, I conclude that there were not enough pots discarded in the village to support the population for a long period of time. In fact, the vessel data collaborates very nicely with the projected occupation length of less than one year.
A collection of Mill Creek pottery vessels.
I conclude that there were approximately 44 pots discarded in the village throughout the period of occupation, too few to support the estimated population for a lengthy period of time.
I would like to thank the Iowa Center for Research by Undergraduates for providing the funding for this project. I also extend my thanks to the Office of the State Archaeologist and the expert staff members who assisted me through all stages of the research process. Special thanks are due to Steve Lensink, Margaret Beck, and Lynn Alex. Photographs and illustrations, except where noted, are courtesy of the OSA.