 The main line of the narrow gauge network runs from Palézieux on the SBB main line from Bern to Lausanne via Châtel-St. Denis and Bulle to Montbovon.The first section from Palézieux to Chatel-St. Denis was opened on 29 April 1901 to be followed by the section to Montbovon in 1904.The main line, which has a length of , makes connection with the Monteux Oberland Bernoise Railway (MOB) at Montbovon.