Mr. Julian, there are 10 members responsible for 11 of the crossings between Ontario and New York and Michigan. The anomaly is that on the Canadian side, the Blue Water Bridge is operated by the Blue Water Bridge Authority, a Canadian crown corporation, and it's operated by the Michigan Department of Transportation on the U.S. side.
The other anomaly is that the Niagara Falls Bridge Commission is the only entity responsible for multiple crossings--the Rainbow, Whirlpool Rapids, and Lewiston-Queenston bridges.