Mystery Theme # Whatever by FlaxmanR

Question 8

It is one of 14 rivers designated an American Heritage River, and is the only one to also be one of the 38 designated Canadian Heritage Rivers. Technically more a strait than a river, it runs 28 miles as a connection between two lakes, one of which is much larger than the other. What river’s crossings include the Grosse Ile Toll Bridge, MacArthur Bridge, and most notably the Ambassador Bridge, the only one that completely crosses it?