In the second half of the 19th Century the BME began to provide connections from its main line, the Elberfeld–Dortmund railway, to isolated places in the western Sauerland.

This branch started from Iserlohn-Letmathe station in the Genna district, which five years earlier had been opened by the BME on the Ruhr–Sieg railway from Hagen to Siegen.

On 17 April 1873 the BME had signed a contract to build a line and secured funding from the Prussian ministry of trade.

[2] From 11 June 2007 to 31 May 2008, this siding was then rented by the town of Hemer to carry uprooted trees after hurricane Kyrill.

In November 2007, the Hemer transport committee decided that it no longer wish to pursue this idea because in the opinion of experts no rail services would result.

But in order to restore the track, the Rhein-Sieg-Eisenbahn GmbH (RSE), based in Bonn, filed a lawsuit in the autumn of 2008 against the Federal Railway Authority (Eisenbahn-Bundesamt) in the Administrative Court in Arnsberg to prevent the imminent dismantling of the tracks and filed an application for the authority to operate the line as a railway infrastructure company.

The RSE would withdraw the lawsuit if the town of Hemer negotiated a cooperative agreement for the reactivation and operation of the line.

The local CDU leader Martin Wächter would only make a decision on a possible dismantling of the railway when the results of a potential study by Zweckverbands Schienenpersonenverkehr Ruhr-Lippe (Association for Passenger Rail Transport of Ruhr-Lippe, ZRL) presented the opportunities for realising a Hemer–Menden–Dortmund service.

After the timetable change on 9 December 2007, Abellio Rail NRW operated passenger services over the Ruhr-Sieg Network as a result of winning a contract in the summer of 2005 for the twelve years up to 2019.

[7] As a result of the insolvency of Abellio in July 2021, DB Regio was commissioned with the traffic on the route from 1 February 2022 to December 2023 by direct award.