Prairie Smoke Karst Sinkhole tour- August 23rd, 2025 Prairie Smoke arranged a tour on August 23rd, 2025 of several Karst topography features including sinkholes and a large spring, guided by retired MN DNR hydrologist Jeff Green. The Driftless Region with its unique Karst topography encompasses parts of SE Minnesota, Wisconsin and Iowa. We toured near Fountain MN, “Sinkhole Capital of the USA”. Starting on 320th Street at the intersection with Highway 52, south of Chatfield, near the Parsley Bridge Canoe Access, we viewed a road cut showing some of the exposed limestone strata typical of this region. From there we drove to Fountain and walked a quarter mile down the Root River Trail to the Sinkhole Education Kiosk where we were able to take a close-up look at a sinkhole as Jeff provided detail about stormwater as it relates to sinkholes. From there, we drove to the Fountain Big Spring, five minutes from the city. This spring is connected to several local sinkholes and runs cold water year-round. In the past, local youths stored watermelons in the stream until they were washed away by increased flow after a large rainstorm! The tour wrapped up around 3:00 pm when we met at the Karst Brewery in Fountain for further discussions of sinkholes and prairies.