Driftless Area

The Driftless Area is the corner of Wisconsin, Iowa, Minnesota, and Illinois that the glaciers went around, leaving steep bluffs, deep valleys, and cold spring-fed streams instead of flat till. Galena, La Crosse, Dubuque, and Decorah sit in that terrain, and its dry south-facing bluff prairies hold plants found nowhere else in the upper Midwest. Natives like prairie dropseed, sweet coneflower, and Short’s aster suit those bluff prairies and the thin soil sitting on top of them.

Conditions: Thin soils over limestone bluffs with deep loess ridges, 32–36 inches of precipitation, cold winters, warm summers, steep slopes.

Cities and areas: Galena, La Crosse, Dubuque, Decorah, Viroqua, Prairie du Chien.