The pass was an important trade route over the Alps during the Middle Ages. In 1410 several communities north and south of the pass agreed to work together to maintain the path. In 1512 the Three Leagues and their Swiss allies invaded the Valtellina region through the Bernina Pass. Around this time the route over the pass was described for the first time. It covered a distance of about 20 miles (32 km) from Poschiavo to Pontresina.[1]
The building of the road began in 1842. Head of engineers was Rudolf Albertini (1821–1896) from Zuoz. The work was finished in 1865 and a hospice at an elevation of 2,307 metres (7,569 ft) was also opened. Since this time the road has been widened several times. Since 1965 it has been open all year round, although there is snow during 8 months.
Climate
Climate data for Passo del Bernina: 2260m (1991–2020)
^"Climate Norm Value Tables". Climate diagrams and normals from Swiss measuring stations. Federal Office of Meteorology and Climatology (MeteoSwiss). Archived from the original on 26 September 2015. Retrieved 5 January 2016.