The Duisburg-Ruhrort–Dortmund railway (also called the Cologne-Minden Emscher Valley Railway) was built by the Cologne-Minden Railway Company (Cöln-Mindener Eisenbahn-Gesellschaft, CME) in the area to the north of its original Ruhr line to improve connections to mines and factories in the northern Ruhr region, which is now in the German state of North Rhine-Westphalia.