These caves in SE MN are in whats called the 'Driftless Area' [0] because it was -not- covered by ice (which would have left 'drift' behind) during recent glaci

These caves in SE MN are in whats called the 'Driftless Area' [0] because it was -not- covered by ice (which would have left 'drift' behind) during recent glacial periods. But it -was surrounded- by ice. You might guess that as a result many of the caves may have been created by draining meltwater. As a result, Ackerman may not have enough money to corner the market! [0] https://en.wikipedia.org/wiki/Driftless_Area https://en.wikipedia.org/wiki/Driftless_Area