Seas eventually covered most of what is now Kansas and the exposed land surfaces laid to the east. With some exceptions, these sandstone bodies are oriented in an east-west direction, parallel to the drainage direction. The shoreline sandstone bodies occur in the upper Dakota Formation and the Kiowa Formation. The long axes of these sandstone bodies tend to be oriented in a north-south direction, parallel to the orientation of the ancient shorelines. Both river-deposited and shoreline sandstones occur in the lower part of the Dakota aquifer throughout its extent.
Arrows represent flow toward the well.
Lighter shading represents the volume affected by pumping a single well.