Fillmore County: The Driftless Area

Fillmore County in southeastern Minnesota sits squarely inside the Driftless Area, a geological anomaly covering parts of Minnesota, Wisconsin, Iowa, and Illinois that the last glaciers never touched. While ice sheets a mile thick flattened nearly everything else in the upper Midwest, this region was bypassed, leaving its ancient topography of steep river bluffs, winding valleys, and exposed limestone intact. The result is a landscape unlike anything else in the region: trout streams running cold through karst formations, sinkholes, and caves carved by water dissolving the limestone beneath the surface.

Fillmore County is dotted with sinkholes. The Root River winds through this county on its way to the Mississippi, and the bluffs rising above its valley are among the most dramatic terrain in Minnesota. Lanesboro, the county's best-known town, sits at the bottom of one of those valleys, cut by the Root River and its tributaries.