thumb|320px|Main chain of the Alps

The main chain of the Alps, also called the Alpine divide is the central line of mountains that forms the drainage divide of the range. Main chains of mountain ranges are traditionally designated in this way, and generally include the highest peaks of a range. The Alps are something of an unusual case in that several significant groups of mountains are separated from the main chain by sizable distances. Among these groups are the Dauphiné Alps, the Eastern and Western Graians, the entire Bernese Alps, the Tödi, Albula and Silvretta groups, the Ortler and Adamello ranges, and the Dolomites of Veneto and South Tyrol, as well as the lower Alps of Vorarlberg, Bavaria, and Salzburg.

Main features

The Alpine Divide is defined for much of its distance by the watershed between the drainage basin of the Po in Italy on one side, with the other side of the divide being formed by the Rhone, the Rhine and the Danube. Further east, the watershed is between the Adige and the Danube, before heading into Austria and draining on both sides into the Danube. For much of its distance the watershed lies on or close to the Italian border, although there are numerous deviations, notably, the Swiss canton of Ticino which lies south of the range in the Po river basin.

For only a small portion of its total distance does the Alpine divide form a part of the main European watershed, in the central section where the watershed is between the Po and the Rhine.

The Alps are generally divided into Eastern Alps and Western Alps, cut along a line between Lake Como and Lake Constance, following the Rhine valley.

  • The Eastern Alps (main ridge elongated and broad) belong to Austria, Germany, Italy, Slovenia, and Switzerland.
  • The Western Alps are higher, but their central chain is shorter and much curved; they are located in France, Italy, and Switzerland.

Piz Bernina (4,049 metres) is the highest peak of the Eastern Alps while the highest peak of the Western Alps is Mont Blanc (4,810.45 metres).

Eastern Alps

thumb|Main ridge ([[Fuscherkarkopf) in the Hohe Tauern range]]

From the Maloja Pass (1,815 m) the main watershed dips to the south-east for a short distance, and then runs eastwards and nearly over the highest summit of the Bernina Range, Piz Bernina (4,049 m), to the Bernina Pass. From here the main chain is less well defined, it rises to Piz Paradisin (3,302 m), beyond which it runs slightly north-east, east of the Italian resort of Livigno, past Fraele Pass (1,952 m) and the source of the Adda, traverses Piz Murtarol (3,180 m) and Monte Forcola, where is the tripoint between the Danube, Po and Adige basins, then falls to the Ofen Pass (2,149 m), soon heads north and rises once more in Piz Sesvenna (3,204 m).

The Reschen Pass (1,504 m) marks a break in the continuity of the Alpine chain. The deep valley, the Vinschgau of the upper Adige, is one of the most remarkable features in the orography of the Alps. The little Reschen Lake, which forms the chief source of the Adige, is only 4 metres below the Pass, and 8 km from the Inn valley. Eastward of this pass, the main chain runs north-east to the Brenner Pass along the snowy crest of the Ötztal, the highest point being the Weißkugel (3,739 m), then crossing the Timmelsjoch (2,474 m) and rising again in Stubai Alps. Both the highest summits of the Ötztal and the Stubai, the Wildspitze (3,774 m) and the Zuckerhütl (3,505 m), stand a little to the north.

The Brenner (1,370 m) is the lowest of all the great road passes across the core part of the main chain and has always been the chief means of communication between Germany and Italy. For some way beyond it, the watershed runs eastwards over the highest crest of the Zillertal Alps, which attains 3,510 metres in the Hochfeiler. But, a little farther, at the Dreiherrnspitze (3,499 m), the chain splits: the main watershed between the Black Sea and the Mediterranean heads south, along the Rieserferner Group to the Dolomites, and Julian Alps.

The main alpine divide head east, traversing the High Tauern range, crossing the Grossvenediger (3,666 m), passing just north of Austria's highest peak (the Grossglockner), traversing Ankogel (3,252 m), before curving northern across the Lower Tauern, traversing its highest peak, Hochgolling (2,863 m) in the Schladming Tauern and then continuing on the same eastward path up to the Schober Pass in Styria. The drainage divide further runs eastwards through the Northern Limestone Alps, ending at "Vienna Gate", the steep slopes of the Leopoldsberg (425 m) high above the Danube water gap and the Vienna Basin.

Western Alps

Starting from the Bocchetta di Altare or di Colle di Cadibona (west of Savona), the main chain extends first south-west, then north-west to the Col de Tenda, though nowhere rising much beyond the zone of coniferous trees. Beyond the Col de Tenda the direction is first roughly west, then north-west to the Rocca dei Tre Vescovi (2,840 m), just south of the Enciastraia (2,955 m), several peaks of about 3,000 metres rising on the watershed, though the highest of all, the Punta dell'Argentera (3,297 m) stands a little way to its north. From the Rocher des Trois Évêques the drainage divide runs due north for a long distance, though of the two loftiest peaks of this region one, the Aiguille de Chambeyron (3,412 m), is just to the west, and the other, the Monviso (3,841 m), is just to the east of the divide. From the head of the Val Pellice the main chain runs north-west and diminishes much in average height until it reaches the Mont Thabor (3,178 m), which forms the apex of a salient angle which the main chain here presents towards the west. From here the divide extends eastwards, culminating in the Aiguille de Scolette (3,505 m), but makes a great curve to the north-west and back to the south-east before rising in the Rocciamelone (3,509 m). From there the direction taken is north as far as the eastern summit (3,619 m) of the Levanna, the divide rising in a series of snowy peaks, though the loftiest point of the region, the Pointe de Charbonnel (3,760 m), stands a little to the west. Once more the chain bends to the north-west, rising in several lofty peaks (the highest is the Aiguille de la Grande Sassière, 3,751 m), before attaining the considerable depression of the Little St Bernard Pass.

thumb|View of the [[Witenwasserenstock with the tripoint between the Rhone, Rhine, and Po basins (center left)]]

The divide then briefly turns north to the Col de la Soigne, and then north-east along the crest of the Mont Blanc chain, which culminates in the peak of Mont Blanc (4,810 m),