French Jura

The Jura range straddles the border between France and Switzerland.  It begins in eastern France on the northern bank of the River Rhone and then extends northwards along the northern bank of that river and Lac Léman (Lake Geneva) to the Swiss frontier north of Geneva.  From that point it continues as the boundary line between France and Switzerland in a long arc curving to the north-east.  The range eventually passes wholly into Switzerland, ending on the southern bank of the Rhine near Basel.  The range is some 320 km in length, and between 32 km and 56 km in width.

The limestone of which the Jura is formed was laid down in shallow seas of the Jurassic period (205 to 145 million years ago).  It is rock rich in fossils.  Indeed the range gave its name to this period in the Mesozoic Era.  The range consists of a series of parallel folds in the strata forming a high plateau.  The folded ridges are cut by transverse fractures which in places form steep gorges (cluses).  The effects of glaciation can also be seen, particularly on the more steeply scarped southern flanks of the range.  The glaciers have long gone from the range, however, and there is now no permanent snow.

The range was originally mainly forested, even to its lower slopes.  Today the upper slopes remain forested (apart from the highest summits which are open grassland) but the action of man has stripped the middle and lower slopes of their forest cover to leave pasture.

The general altitude of the Jura is between 910m and 1520m.  The range reaches its highest point near the south-western end of the range in France at Le Crêt de la Neige, which has an altitude of 1718m and prominence of 1268m. The highest and most prominent summit of the Bernese Jura in Switzerland is Le Chasseron near Yverdon at an altitude of 1607m and prominence of 614m.

A list of all the mountains and hills of the French Jura to 150 metres of prominence can be downloaded below.