The Great Lakes St Lawrence Seaway Development Corporation (GLS) Regions dataset was compiled January 25, 2023 from the Great Lakes St. Lawrence Seaway Development Corporation (GLS) Policy Headquarters and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). The GLS Region layer containing polygon features the coastal frontage of the eight Great Lakes states along the five Great Lakes including along the St Mary’s River, the St Clair River, the Detroit River, and the St Lawrence River. This region is charged with ensuring the safe, secure, and reliable transit movement of vessel traffic daily into and out of the Seaway system as well as supporting trade development at ports and terminals throughout the system. The jurisdiction of GLS operational staff is limited to the two U.S. locks in Massena, New York as well as navigation on the St Lawrence River immediately to the East and West of those locks. The GLS Trade Development’s direct jurisdiction extends from Massena, New York in the Eastern end of the system to the Minnesota ports of Duluth, Two Harbors, and Silver Bay on Lake Superior to the West and includes all Great Lakes ports/terminals in between.