San Bernardino Pass is a high mountain pass in the Swiss Alps connecting the Hinterrhein and the Mesolcina valleys between Thusis and Bellinzona. Located in the far eastern side of the Western Alps it is not to be confused with the Great St Bernard Pass and the Little St Bernard Pass. The top of the pass represents both the Italo-German language frontier and the watershed between the Po basin and the Rhine basin. Marscholsee is within the pass at an elevation of 2,053 m.
The route first became important as a mule track in the fifteenth century when the route between Thusis and Splügen was known as the Via Mala. A road for wheeled vehicles was opened in 1770; this road was significantly improved between 1821 and 1823, financed in part by the Kingdom of Sardinia, keen to improve a trade route connecting Genoa and Piedmont to the Graubünden that was not directly controlled by Austria.
Wikipedia https://en.wikipedia.org/wiki/San_Bernardino_Pass
Coordinates 46°29'49.735" N 9°10'16.104" E