An Assessment of Prairie Mound Origin Theories
at University of Arkansas Experimental Farms

           
           Gregory Vogel

            Prairie mounds, also known as pimple mounds, "hog-wallows", and Mima mounds (after the type locality at Mima Prairie in Washington State), are somewhat enigmatic landform features.  They occur throughout western North America as fields of low mounds or hillocks, often covered in prairie grasses and usually on current or former floodplains.  I am interested in them archaeologically because they were modified in both prehistoric and historic times, they may be indicators of past environments, and because they have often been mistaken for mounds constructed by people.

            The formation of prairie mounds has been studied and debated for over a century.  Some of the main formation theories include:
            Aeolian: mounds were formed as coppice dunes anchored by vegetation.
            Fluvial: mounds were formed through fluvial erosion of the intervening sediment.
            Fossorial rodent: the burrowing of gophers or other animals formed the mounds.
            Seismic: earth became mounded through shaking during earthquakes.
            Periglacial: mounds are the result of earth movement due to freezing and thawing or other             periglacial processes.

            There is no universal definition of exactly what constitutes a prairie mound field, and this may be the source of debate about their origins.  It seems likely that features termed "prairie mounds" were formed by different processes in different locations.       

            The links above take you to a short paper I wrote concerning prairie mounds in Fayetteville Arkansas, and a list of references and other resources concerning prairie mounds.  You can download a PDF version of the paper here. 

            If you have references or other resources to add, feel free to contact me: ggvogel@gamail.com.

            You can read more of my on-line projects and papers here.