The Great Lakes Saint Lawrence Seaway Development Corporation is an agency within the U.S. Department of Transportation. It operates and maintains the United States portion of the St. Lawrence Seaway, the system of locks and channels that allows ocean-going ships to travel between the Atlantic Ocean and the Great Lakes. The corporation runs the two U.S. locks on the Seaway and coordinates vessel traffic with the Canadian authority that manages the rest of the waterway.
Its work centers on keeping the waterway open and safe for commercial shipping. That includes operating and repairing the locks, maintaining channels, directing vessel traffic, inspecting ships that enter the system, and tracking the cargo moving through it.
The agency employs lock operators, marine traffic controllers, civil, mechanical and electrical engineers, maintenance mechanics, electricians and welders, along with accounting, procurement, human resources and administrative staff. Positions are based at the corporation's headquarters and at its lock and maintenance facilities along the St. Lawrence River.