Source to Sea

S1 E1: The Great Lakes make up the world’s largest freshwater ecosystem, containing as much as one-fifth of the planet’s supply. Each lake is a vast body of water with its own mood and story. And each plays a part in a much larger system, carrying water on a journey that spans half a continent and more than three centuries. Follow its dramatic path east and discover how this enormous watershed nourishes a rich, diverse web of life, from endangered loons and piping plovers and loons to beavers and wolves to monarch butterflies on their epic migrations south.