Todd/Mellette Counties Study

Project Description

This is an investigation of the geology and water resources of a two county area in south central South Dakota. The stratigraphy, sedimentology, and surficial geology are the main areas of emphasis. Surface deposits include:

• Miocene and Pleistocene sand dunes
• Miocene Ogallala Group sands and silts
• Oligocene Arikaree Group siltstones
• Oligocene and Eocene White River Group claystones and late Cretaceous Pierre Shale

Shallow ground water resources are often of exceptionally good quality.