At one time in the 1960's there were three swinging bridges near Warsaw. One was east of the town over the Grand River, one was near the marina in town and the third was seveal miles down 7 Highway I think. There was a little Inn or tavern sort of place on the north side of the bridge. I remember a trucker took too much weight over it, and it went down. He and his wife and child were killed in the accident. Maybe a check in the old papers would lead you to the answer on the names of the bridges
This bridge very well could be the original Upper Bridge in Warsaw. It was destroyed by a tornado in 1924.