Brule County Study

Project Description

Brule County has been lightly and indirectly studied in the past but there is no comprehensive study. Some previous studies include surface geology mapping along the Missouri River in the 1950's and characterization of a landfill site near Pukwana in 1996. This study is a comprehensive analysis of the geology and hydrology of Brule County. The results of this study will be a series of 1:100,000 scale maps of the surface geology, aquifer materials and bedrock elevation. These maps will be complimented by a report further detailing the geology and hydrology in the area. The information is primarily gathered through drilling test holes where descriptions of the lithology are recorded. Field surveys and GIS analysis are also used to support the test hole data. Currently, there is test hole data to support the locations of potentially two Pleistocene aquifers. One location is an alluvial aquifer that follows the Smith Creek valley. The other location follows a bedrock channel that likely runs east-west through the middle of the county. More data is needed to confirm that these bodies of sand and gravel are substantial enough to be considered an aquifer unit.

The base map in this figure is a 0.5-meter DEM showing the surface terrain. Overlayed on top of the DEM are the completed test holes (white points), road network (black and red lines), Pierre Shale outcrops along the Missouri River (green lines), and the location of a potential alluvial aquifer (red line in the north).