From source: http://www.wmwestsub.com/ State Line Jct. was where the two former main tracks between Colmar and Cumberland was later reduced into one single track for the trip west up the mountain. The only stretch of double track became the Mt. Savage siding between Mt. Savage and Frostburg. Back at State Line Jct. a branch ran off to the right across a curved bridge spanning Rt. 40, Will's Creek, C&P Eckhart Branch, and the B&O. The State Line Branch ran to State Line, Pa. where it connected with the Pennsylavania Railroad. The PRR had trackage rights over the WM into Cumberland.
Today not much is left at State Line Jct. It is still possible to see exactly where the train-order office was and the brisge for the State Line Branch. Nothing here today but a few power poles and the WM's thru-truss bridge that the Western Maryland Scenic Railroad now uses.