The line from Altstätten Stadt (town) via Stoss to Gais—where there was a connection to the line of the St. Gallen-Gais-Appenzell-Altstätten-Bahn (St. Gallen-Gais-Appenzell-Altstätten Railway) to St. Gallen—was opened on 18 November 1911 and operated with three CFe 3/3 class railcars.