From the beginning, an extension over the San Bernardino Pass to Thusis was planned, in order to provide a rail connection to the Rhaetian Railway (RhB), but this was not constructed. In 1942 the line was merged into the RhB, but it was never connected to that railway's main network. In 1972, all passenger traffic ceased and the line between Bellinzona and Castione-Arbedo was closed, whilst freight traffic continued on the rest of the line.