Wisconsin is better known for trees, cows, and snow than for cactus. Even so, multiple species of prickly pears have a native range extending to the Upper Midwest. The cacti are not abundant, but they can flourish in the micro-climates created by well drained, sunny slopes in the Driftless Area.
These wild prickly pear cacti grow along a south facing outcrop of St. Peter sandstone in southwest Wisconsin. I was lucky enough to find them just in time for their short lived yellow blossoms in early July.