What river is part of the segway connecting the five great lakes to the Atlantic ocean?

The St. Lawrence River is the key waterway that connects the Great Lakes to the Atlantic Ocean. It flows from Lake Ontario, through the province of Quebec in Canada, and eventually empties into the Gulf of St. Lawrence. This river is a vital part of the Great Lakes-St. Lawrence Seaway system, facilitating maritime trade and navigation between the interior of North America and the ocean.