The Pyhrn Pass, 945 m above sea level, is the lowest passage across the eastern Alps, and has been used since the Neolithic Age.
In Roman times, the pass was crossed by a post road. In 1190, Bishop Otto II of Bamberg founded a hospice on the Pyhrn. With the development of industry, in particular the working of iron in the Enns Valley and the scythe making in the Pyhrn region, the Linz Diet began as early as 1866 to think about a railway link. The project was postponed in favour of the "Crown Prince Rudolf Railway" through the Enns Valley. This led to the foundation of the Kremstalbahngesellschaft company, which used private funds to build a railway from Linz to Klaus-Steyrling via Kremsmunster. It was not until the beginning of 1901 that the legal basis for the construction of a railway from Klaus to Selzthal was adopted, as part of the government "New Alpine Railways" project intended to prevent the collapse of the port of Trieste. In the light of the need for suitable gradients, the Bosruck route was chosen over the Pyhrn.
Work was ceremoniously started on July 1, 1901 at Spital am Pyhrn. The approach sections were constructed from 1903 to 1905 at the same time as the tunnels, at times using considerable technical outlay. Disastrous flooding delayed the completion of the 4470 metre long Bosruck tunnel, which was ceremoniously opened on August 21, 1906. On the day before it opened, the last post coach travelled over the Pyhrn Pass. The 104 km long single-track route of the Pyhrn Railway from Linz to Selzthal is still today primarily used for goods traffic. Of course, it also caused a boom in tourism in the Pyhrn-Priel region. The railway nevertheless remained of marginal value, since the collapse of the Empire and the loss of Moravia meant that the north-south link was only of local relevance. The route was renovated between 1963 and 1965, the Bosruck tunnel in particular having suffered such huge damage from steam railway operations that it had to be closed completely for two years. It was only between 1975 and 1977 that the line was electrified.
The route of the Pyhrn Railway is continuously being improved. For goods traffic, for instance, a new loop to the Western Railway was built, cutting 90 minutes off travelling times and relieving Linz station of considerable traffic. In recent years the railway has acquired powerful competition in the form of the Pyhrn Motorway, and has lost its former importance in freight transport. Although the Pyhrn railway is part of the Trans European Network, further improvement is not a top priority. On the occasion of the anniversary of the railway in 2001, Elmar Oberegger published a detailed "History of the Pyhrn railway".