Indiana Dunes National Park, authorized by Congress in 1966, is located approximately 50 miles southeast of Chicago, Illinois in the counties of Lake, Porter, and LaPorte in Northwest Indiana. The national park runs for nearly 25 miles along southern Lake Michigan, bordered by Michigan City, Indiana on the east, and Gary on the west. The park contains approximately 15,000 acres, 2,182 of which are located in Indiana Dunes State Park and managed by the Indiana Department of Natural Resources. Miles of beaches, sand dunes, bog, wetlands, woodland forests, an 1830's French Canadian homestead, and a working 1900 era farm combine to make the national park a unique setting for studying humans and their impact on the environment. Dr. Henry Cowles conducted his landmark ecological studies in the Indiana Dunes. Indiana Dunes is ranked 7th among national parks in native plant diversity. Research conducted over the last two decades has revealed 1,418 vascular plant species within park boundaries, of which over 90 are on the state of Indiana's threatened or endangered list.