The Saint Marys River is a significant waterway located in the United States and Canada. It serves as a natural border between the state of Michigan and the province of Ontario. The river flows from Lake Superior to Lake Huron, playing a crucial role in the Great Lakes system. This river is approximately 70 miles long and is known for its scenic beauty and recreational opportunities. It is also an important shipping route, facilitating the transport of goods between the Great Lakes and the Atlantic Ocean. The river supports various ecosystems and is home to diverse wildlife.