Some 10,000 years ago, glaciers from the last Ice Age were retreating from the Upper Midwest. While much of Wisconsin was scraped into the rolling landscape that is representative of much of the state, a roughly 24,000 square mile piece of land at the intersection of Wisconsin, Minnesota and Iowa, was left untouched by continental glaciers. Broad ridge tops with shallow soil, river-formed valleys, and steep, craggy ravines make the Driftless area a geological anomaly. For millennia, this was a fertile Brook Trout habitat but in an evolutionary blink of an eye, these waters became threatened by modern agriculture. Across this region of sandstone and dolomitic limestone bedrock, there is more than 6,000 miles of trout water, with about 1300 miles of public access. But the health of these waters continue to compete with agriculture to survive.