GARY, Ind. (AP) — Just southwest of the South Shore commuter rail line tracks and the Indiana Toll Road at Burr Street in Gary, 120 acres of land tell the environmental history of Northwest Indiana.

Ivanhoe Dune and Swale, managed by The Nature Conservancy’s Southern Lake Michigan Rim Project office in Merrillville, was formed when Lake Chicago receded thousands of years ago, leaving linear sandy ridges with parallel wetlands called swales between.