Great Blue Heron (Ardea herodias) on Animal Diversity Web at UM – where you can get complete information, pictures & sounds – says that these birds are the largest and most common herons in North America. The Michigan DNR’s Blue Heron page explains that:
This is the familiar, large grayish-blue heron seen wading in shallow water in marshes, ponds and along lakeshores and stream edges. They are sometimes confused with the sandhill crane; the heron is smaller and flies with its neck folded back, while cranes fly with their neck extended. Great blue herons are commonly seen in small suburban wetlands (cranes are generally less tolerant of close presence). Herons feed on fish, frogs, and other small animals, captured by a quick jab of the beak. They nest in colonies, usually building their stick platform nests in trees in lowland hardwood swamps. In recent years many rookeries have been displaced by shoreline development or timber cutting. Every attempt must be made to preserve known nesting sites if these beautiful birds are to remain common in Michigan’s wetlands.
Wikipedia has more about the Great Blue Heron and you can get more info (and typical calls) from All About Birds. There’s even a short video of a Michigan blue heron on the Kalamazoo River on YouTube.
Nathan says he looked out the window, saw this guy chillin’ by the frog pond and couldn’t believe his eyes when he stretched his neck. Be sure to check this out bigger or in his Great Outdoors set (slideshow).