Frequently Asked Questions

How can I obtain information about test holes and observation wells that have been drilled in the state?
The Geological Survey Program maintains databases of test holes and observation wells. If you want to know what is available in any specific location, you can contact the Geological Survey Program and request site-specific information, or visit the SDGS Interactive Map to view an interactive map and download information.

Are there any maps showing the location of the aquifers near my land?
The Geological Survey Program publishes reports that describe the geology and hydrology of the state. These reports contain maps and figures that show the locations of the aquifers. These reports can be obtained by contacting the Geological Survey Program.

How many earthquakes have been recorded in South Dakota?
Eighty-seven earthquakes have been recorded with epicenters in South Dakota from the years 1872 through March 2012. The first one to be recorded was about 25 miles north of Pierre in February of 1872. The most recent was a 3.0 magnitude (Richter scale) quake in Shannon County in January 2012. View our Earthquakes page to see the locations of recorded earthquakes in South Dakota.

Are there any oil and gas wells in South Dakota?
Yes, as of October 2022 there are 151 oil wells and 42 gas wells in production. Oil was first discovered in Harding County in 1954, with later discoveries as far east as the Lantry Field in Dewey County and as far south as Fall River County. More information can be found on the Minerals and Mining Program's Oil and Gas Section website. or South Dakota's Oil and Gas Initiative website.

How do I obtain reports and maps from the Geological Survey Program?
Reports and maps can be ordered directly from the Geological Survey Program. A document listing all of the Geological Survey Program publications is available in paper format at no charge and is available for free download. The Geological Survey Program is an Earth Science Information Center. This means we are an authorized dealer of U.S. Geological Survey maps and other products. The Geological Survey Program has an inventory of all topographic maps of the State of South Dakota.

I just purchased land in the Black Hills. How do I develop a good quality water well and how deep will it need to be?
A person should always check into the potential water supply before purchasing the land. In some areas, the water bearing materials are very deep and it is expensive to drill for water. Other areas may have water quality problems or may not yield sufficient quantities of water to supply a household. Check with the Geological Survey Program for specific site information.