John Winfield. A big Pennsy Class M1 "Mountain" locomotive swings off Rockville Bridge, just north of Harrisburg, Pennsylvania, and into Enola Yard while M1a #6783 pulls out with westbound tonnage. The Pennsylvania Railroad completed the famous Rockville Bridge, the longest stone arch bridge in the world, in 1902. 24"x 18" limited edition print is signed and numbered by the artist. #0R07315