The railways arrived in Black Mount in July 1864, with the opening of the Leadburn, Linton and Dolphinton railway, the Act establishing the line having received Royal Assent two years earlier. It was a branch line running off the Peebles railway at Leadburn, with stations at Lamancha, Macbie Hill (originally called Coalyburn) and Broomlee (for West Linton).

A locomotive shed was built at Dolphinton in July 1864, with a turntable and water tank, reflecting the importance of the first railway line in the area. In 1866, the Leadburn, Linton and Dolphinton railway was absorbed by the North British Railway.

A year later, in March 1867, the Caledonian Railway opened its own line from Carstairs to Dolphinton, 11 miles in length, with stations at Bankhead, Newbigging and Dunsyre. For its construction, capital of £105,000 in shares and £35,000 in loans was raised.

Although logic might indicate that this created a through line from Carstairs to Leadburn, and on to Edinburgh, in reality the two railway companies could not agree on terms, and an awkward connection at Dolphinton ensured that there was never a through service.

In 1896, following a significant increase in traffic, the Caledonian railway built a turntable at Dolphinton to the west of the station. Further traffic growth resulted in a locomotive shed being built at Dolphinton in 1906. However, this growth could not be sustained, and in December 1915 the shed was closed.

Both lines suffered from a loss in traffic in the years after the First World War, and especially in the late 1920s as road transport, both private and commercial, developed. The routes were closed to all traffic in April 1933, and the Caledonian shed was demolished in May that year.

In 1939, the track from Leadburn to Macbie Hill was re-opened briefly, but services through Black Mount were never re-established.

A few railway remains can still be seen on the route. The North British terminus of the line at Dolphinton survives as a house, and the stone built locomotive shed still stands. It is possible to walk along many stretches of the line, especially in the Dunsyre area.