The Rockaway Loop was part of the original Morris and Essex Railroad mainline, which ran through Rockaway to serve the town's mining and iron industries. After the Morris and Essex Railroad became part of the Delaware, Lackawanna and Western Railroad in 1868, four miles of new track were constructed south of the loop to provide a direct Denville Junction-Dover connection. The tracks between Denville Junction and Rockaway were then retained as a branch known as the Rockaway Loop, and service along it ended in 1948.