On 10 August 1904 the Bavarian state government authorised the construction of a 26.9 kilometre long branch from Waldkirchen to the Czech border beyond Haidmühle.

The route ran from Waldkirchen initially in an easterly direction to Neureichenau and then northeast towards the border station, gaining 346 m in height.

In its early years and after the forced annexation of the Sudetenland through trains ran from Passau to Haidmühle, whilst the Freyung line was given at junction at Waldkirchen.

Plans from the Czech side to extend the route again to Haidmühle, in order to build a better connexion there to Bavarian bus services, were scrapped.

From the early 1930s to the start of the Second World War four-wheeled diesel railbuses of DRG Class 135 and 137, together with their corresponding trailer cars, also ran to Freyung and Haidmühle.