Central Michigan Railway

Reporting mark: CM
CM - Bay City Swing Bridge (Bay County, Michigan)
Pratt through truss bridge over Saginaw River on Central Michigan Railway
Open to traffic

CM - Saginaw River Swing Bridge (Saginaw County, Michigan)
Built 1914
Baltimore through truss bridge over Saginaw River on Central Michigan RR
Open to traffic (though no longer as a swing)