There are thirteen resorts in the Portes du Soleil area, of which seven are French and five are Swiss. Most of the resorts have grown around traditional valley villages - only Avoriaz and the very small Les Crosets and Torgon were purposely built during the mid-sixties. Morzine and Chatel are the largest of the traditional towns in the area. As a whole the skiing is relatively low in altitude compared to most French destinations. The highest skiing is just below and the lowest is approximately . However, the area is heavily influenced by the microclimate between Lake Geneva and Mont Blanc, which generates very substantial snowfall between November and April making it possible to keep the area open to skiing typically from early December until mid to late April. Some of the lower stations close around April 1 or earlier depending on snow conditions though.