 The United States Department of the Interior recognized the southern section of the Air Line State Park Trail as a national recreation trail in 2002.Envisioned as a high speed passenger railroad line from New York to Boston, the New Haven, Middletown and Willimantic Railroad (NHM&W) got its name from the towering iron viaducts constructed to create a level track bed suitable for rapid travel.Opened in 1873 as part of the Boston, Hartford and Erie Railroad (BH&E) system, it ran from New Haven northeast via Middletown to the BH&E at Willimantic.