Karst is a little-known but unique and important landform that can be found throughout the state of Ohio. Sinkholes are the main hazard associated with karst landforms in Ohio and there are thousands of them in the state.  Regions that contain sinkholes and other solutional features, such as caves, springs, disappearing streams, and enlarged fractures, are known as karst terrains.

Sinkholes form as bedrock dissolves and surface materials erode or collapse into the resulting voids. In Ohio, karst forms largely in the Devonian-, Silurian-, and Ordovician-aged bedrock in the central and western portions of the state. Learn more about Ohio's bedrock here.

The ODNR Division of Geological Survey appreciates information submitted by the public that will help identify karst features. Report sinkholes and other karst features using our online form.

Karst Interactive Map

The ODNR Division of Geological Survey has been mapping karst in Ohio since 2011. Released in 2019, the Karst Interactive Map is a record of karst features found throughout Ohio that is updated regularly as mapping continues. Each datapoint links to a list of information about the feature, including location; feature type; notes and comments about the location or feature; and photograph(s), if available.

For detailed information about specific karst features or to check your location of interest for karst features, input the address information into the Address/Coordinate Search menu, and then click on the feature of interest. Also, the current Ohio karst GIS dataset can be downloaded (for use in GIS) via the introduction screen that appears when the map is first launched.

Karst in Ohio (Video)

The video below provides a brief overview of karst landforms in Ohio and the ODNR Division of Geological Survey’s efforts to research and map them. These geologic hazards, which include sinkholes, disappearing streams, and caves, affect the way we live and impact how we use natural resources and the land around us.