It was built in order to enable the Magdeburg-Halberstadt Railway Company (Magdeburg-Halberstädter Eisenbahngesellschaft or MHE) to access the mines in the Harz mountains.

Its original passenger services to Langelsheim on the Vienenburg–Langelsheim railway via Grauhof ended as early as 1884 and all traffic ceased in 1954; a direct line to Goslar being employed instead.

In 1874 the Magdeburg-Halberstadt Railway Company began work and bored a tunnel through the Gallenberg in Wildemann, which was finished in July 1875.

More and more mines were closed, the Second World War took it one stage further and in the mid-1950s mail services between Goslar and Altenau were withdrawn and transferred to the road.

At the beginning of the 1960s significant construction work was needed and the line had to be moved when the valley was flooded during the building of the Innerste Dam.

The old trackbed of the Innerste Valley Railway is now a walking and cycle path in summer and a cross-country skiing trail in winter.