The Chicago River is the back door of Lake Michigan – connecting Chicago to the Mississippi River and the rest of the world. But there's another water superhighway for big cargo ships. That’s the front door – otherwise known as The St. Lawrence Seaway. It stretches more than 2,000 miles from Lake Ontario to the Atlantic Ocean. Construction of the route in the 1950s transformed the economy and the ecology of the Great Lakes. North Country Public Radio Adirondack bureau chief Brian Mann is travelling the waterway as part of the series Front and Center and he joined Eight Forty-Eight to explain more about his journey.