Greywacke gave reason for the construction of the "Wiehltalbahn (Wiehl Valley Railway)": numerous quarries in the Wiehl area, especially in the Alpe valley, had to carry their goods either to Ründeroth in the Agger valley to the "Aggertalbahn (Agger Valley Railway)" or to Waldbröl to the "Bröltalbahn (Bröl Valley Railway)". So the opening of the Wiehltalbahn line up to Wiehl in 1897 meant a substantial improvement for the quarrying companies - and the increasing disposal of the quarries drove the traffic on the Wiehltalbahn.
Important dates:
- April 21st, 1897: Opening of the Osberghausen - Wiehl section
- December 15th, 1906: Opening of the Wiehl - Waldbröl section
- October 1st, 1908: Opening of the Hermesdorf - Morsbach section and by that linked to the 18 years older line Wissen - Morsbach
- October 2nd, 1960: Discontinuation of public transport on the Hermesdorf - Morsbach branch
- September 26th, 1965: Discontinuation of public transport between Osberghausen and Waldbröl
- September, 1994: Last freight train Hermesdorf - Morsbach
- October 05th, 1994: Last freight train Osberghausen - Waldbröl
- October 10th, 1994: Formation of the "Förderkreis zur Rettung der Wiehltalbahn e.V. (Fund Raising Group For The Preservation Of The Wiehl Valley Railway - association serving the public good)"
- 1998: Leasing of the line by the "Förderkreis zur Rettung der Wiehltalbahn e.V."; cooperation treaty with the Rhine-Sieg-Railway Ltd. ("Rhein-Sieg-Eisenbahn" - RSE ) in Bonn-Beuel. Since then intense works by members of the Fund Raising Group under the guidance of the RSE on the entire line Osberghausen - Waldbröl - Morsbach
- December 4th, 1999: Re-opening of the Osberghausen - Wiehl section, initially by touristy train service
- August 27th, 2000: Re-opening of the Wiehl - Oberwiehl section
- 2000: First freight train on the revived Wiehltalbahn
- December 15th, 2006: The adjacent municipalities bought the Wiehltalbahn line to lift it, followed by long-lasting political controversies including court actions.
- 2007: Intensive freight traffic for the first time since its termination on October 05th, 1994. All the year storm-damaged timber (thunderstorm "Kyrill" on January 18th, 2007) was routed
- October 10th, 2009: For the first time since the service termination the maintenance train reaches Waldbröl again
- 2009: The courts confirm the right of continuance for the line in several findings. The line has to remain a railway line. The findings become well-known among experts as "Wiehltalbahn-Verdicts". Local politics start to deal constructively with the "Wiehltalbahn" project
- April 18th, 2010: Re-opening of the Oberwiehl - Waldbröl section and simultaneously the premiere ride of the "Bergischer Löwe"
- March 02nd, 2011 / May 24th, 2011: RSE signs lease contracts with the muncipalities. "Förderkreis zur Rettung der Wiehltalbahn e.V." and RSE become co-operation partners.