The landscape of the Calumet, an area that sits astride the Indiana–Illinois state line at the southern end of Lake Michigan was shaped by the glaciers that withdrew toward the end of the last ice age—about 45,000 years ago. In the years since, many natural forces, including wind, running water, and the waves of Lake Michigan, have continued to shape the land. The lake's modern and ancient shorelines have served as Indian trails, stagecoach routes, highways, and sites that have evolved into many of the cities, towns, and villages of the Calumet area. People have also left their mark on the landscape: Indians built mounds; farmers filled in wetlands; governments commissioned ditches and canals to drain marshes and change the direction of rivers; sand was hauled from where it was plentiful to where it was needed for urban and industrial growth. These thousands of years of weather and movements of peoples have given the Calumet region its distinct climate and appeal.