USGS Water Resources IWAA Project: The Cambrian-Ordovician aquifer
![Grey map of the Midwest with the Cambrian-Ordovician aquifer system highlighted in blue](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/cambrianOrdovician.jpg?itok=w_k0HvYG)
Detailed Description
USGS Water Resources IWAA Project: The Cambrian-Ordovician aquifer.
More information at https://www.usgs.gov/mission-areas/water-resources/science/integrated-w…
Sources/Usage
Public Domain.