Finding Lost Graves: Ground Penetrating Radar Analysis of Potter’s Field in Dunn County, Wisconsin, USA

Keywords: GPR, ground penetrating radar, potter's field, archaeology, geoarchaeology
Abstract Type: Poster Abstract

Abstract

The location of over 100 graves at Dunn County Potter’s Field is unknown. Potter’s fields are graveyards for unknown, unclaimed, or impoverished persons, located in most counties in the USA. The site, located in Menomonie, Wisconsin, was active between 1890–1952 and serves as the final resting place for people from the Dunn County Poor House and Farm, and the County Asylum. Most records about Potter’s Field have been lost or destroyed, and current grave markers at the site were only added after 2000. Community outcry for restoration of the site prompted non-invasive scans of Potter’s Field, thus ground penetrating radar (GPR) was utilized. GPR transmits electromagnetic (EM) pulses into the subsurface, where the EM waves reflect off changes in underground material before being received and recorded via a handheld digital video logger. A 16x50-meter grid was collected via a pulseEKKO Pro GPR unit with 500 MegaHertz antennae and 0.25-meter spacing between lines. Local elevation data was collected via a Topcon RL-H4C self-leveling laser and receiver for the purpose of geometrically correcting GPR profile elevation. Numerous anomalies were imaged between 0.6–1.5-meters below the surface, measuring 1.0-meters wide x 2.25-meters long, and spaced 1.0-meter apart. Based on the dimensions of the anomalous patterns, they were interpreted to be probable graves. After a decade of community efforts, in Fall 2024, 42 crosses were placed at each potential burial, however further scanning is required to locate remaining graves. Dunn County Potter’s Field is being restored and provides a model for other communities nationwide.