CRAWFORD COUNTY - Crawford Stewardship Project has completed mapping and reviewing sinkholes in Crawford County using the methodology that was (along with Professor Emeritus Kelvin Rodolfo and our Legion GIS collaborators) developed for the Karst Citizen Science events identifying sinkholes from algorithm-identified points of all closed depressions of two-feet or greater depth. 

At the end of this part of the Karst Landscapes and Groundwater Susceptibility Survey, the findings indicate there are 264 “probable” and 195 “possible” sinkholes—that’s a total of as many as 459 sinkholes in Crawford County.

This qualifies Crawford County as a "high sinkhole density area" (over 25 sinkholes/sq.km., according to the only large scale study done comparing various karst regions of the US).

A sinkhole density ‘heat map’ to show areas of very high concentrations was also developed. This allows for researchers to hone in on particularly susceptible areas.   

Check out the online interactive karst viewer to see the data for yourself:

http://apps.legiongis.com/karstography

Please feel free to play around with the layers in the top right corner (certainly try ‘Hillshade’ basemap).  There are more layers to come that will be added to this interactive platform is being developed.