[1] The first sod was cut on 19 June 1865 by the Duke of Cleveland, who owned a large portion of land that the railway would cross.

Whilst building the line in August 1867, the foreman of works, in a hurry to build a viaduct at Baldersdale, removed the wooden frame from underneath the viaduct being built at Mickleton before the keystone was in place.

[3][4] Built as the southern section of a proposed a line from Barnard Castle to Alston that was never completed the section to Middleton-in-Teesdale was built by the Tees Valley Railway opening on 13 May 1868, with intermediate stations at Mickleton and Cotherstone.

Work started on a reservoir at Grassholme in 1914 and this provided extra traffic with the addition of transfer sidings for the construction site.

[1] Much of the line now forms the Tees Valley Railway Walk, with parking provided at the former site of Mickleton station.