In 1881, it was joined by the Massachusetts Central Railroad (MC), which paralleled it from west of Beaver Street to the Fitchburg Cutoff.

By 1891, the two railroads shared a single Clematis Brook station on the east side of Beaver Street.

[2] (The other stations on the parallel segment – Waverley, Belmont, and Hill Crossing – had separate buildings for the two lines into the 20th century.

In 1952, the B&M abandoned the duplicate Central Mass tracks during a grade separation project at Waverley.

After the track consolidation, the Central Mass Branch diverged from the Fitchburg mainline just west of Clematis Brook.