Geophysical Investigations o f the Plum Creek Massacre Site (25PP24) along the Oregon National Historic Trail in Phelps County, Nebraska

The geophysical survey of the native pasture on the Holen family farm was conducted as part of the National Park Service's technical support of the National Historic Trails Office's investigation of the Plum Creek Massacre Site's archeological potential between August II and August 17, 2009. The geophysical inventory of the project area consisted of a magnetic survey with a dual fluxgate gradiometer across the entire field, a limited resistance survey with resistance meter and twin probe array, a limited conductivity survey with an electromagnetic induction (conductivity) meter, and selected ground penetrating radar surveys with a gps cart system and 400 mHz antenna. A metal detector survey and ground truthing investigations were also conducted on the Holen property and the neighboring Carlson property. The geophysical survey of the site resulted in the identification of numerous subsurface anomalies associated with the Oregon National Historic Trail, as well as possible geophysical anomalies associated with the destruction of the wagons in the Morton freight train and the mass grave of the teamsters.