Valais, canton, southern Switzerland. It borders Italy to the south and France to the west and is bounded by the cantons of Vaud and Bern on the north and Uri and Ticino on the east. Its area includes the valley of the upper Rhône River, from its source at the Rhône Glacier to its mouth on Lake Geneva; the valley runs from east to west and then, in a right angle at Martigny, from southeast to northwest. From just above Saint-Maurice, the Rhône’s right bank belongs to Vaud canton. The mountain chains of the Bernese and the Pennine Alps border the Rhône River valley, and on each side lateral valleys open; those of the south are spread out and inhabited, and those of the north are steep and largely uninhabited, with the exception of the Lötschental (Lötschen Valley) and Leukerbad (Loeche-les-Bains).
The region first appeared in the account of Julius Caesar’s conquest of the Celts at Octodurum (Martigny) about 57 bc. It was originally called Vallis Poenina (“Upper Rhône Valley”). Part of the kingdom of Jurane Burgundy from 888, Valais was granted in 999 by King Rudolf III of Burgundy to the bishop of Sion, who became prefect, count of Valais, and later prince-bishop. The area’s subsequent history was mostly related to the struggles of the patriots against their episcopal overlords and of the bishops against the dukes of Savoy, who coveted their land. Efforts to Protestantize Valais during the Reformation were unsuccessful. The prince-bishops retained their power until the revolution of 1798, when Valais became part of the Helvetic Republic. Napoleon made Valais the independent Rhodanic Republic in 1802 and incorporated it into France as the département of Simplon in 1810. In 1815 Valais entered the Swiss Confederation. Although it took part in the conservative Sonderbund (a Roman Catholic separatist league) in 1845, it did not fight but submitted to federal forces in 1847.
The canton is thinly populated, with no major cities; Sion (q.v.) is the capital and major town. Of the total territory, only about half is productive, with mountain pasture, glaciers, and forest covering the rest. Valais has at least 50 peaks (notably the Matterhorn) exceeding 13,000 feet (4,000 m); these contribute to the economic importance of the resort and tourist industries. Although Valaisan agriculture remains largely traditional, milk is carried by pipelines from high pastures to the central dairies. The formerly marshy plain of the Rhône valley has been transformed into the finest orchard in Switzerland. Valais is also Switzerland’s main wine-producing region.
Large hydroelectric plants produce a quarter of the nation’s power; the tallest gravity dam in the world (at 7,759 feet [2,365 m] above sea level), the Grande Dixence (see photograph), is in the Hérémence valley. Metal products and chemicals are manufactured in the canton, with plants near Sierre, at Visp, and at Monthey. An oil refinery is located at Collombey-Muraz. The canton is served by an airport at Sion and numerous railways and by roads extending through the famous Simplon, Great St. Bernard, and Grimsel passes. Cableways are numerous as a means of transport. The highest cableway in Europe, to the Klein-Matterhorn, 2.4 miles (3.8 km) long and reaching an elevation of 12,533 feet (3,820 m), began operation in 1980. The population is about two-thirds French speaking and one-third German speaking and about nine-tenths Roman Catholic. Area 2,017 square miles (5,224 square km). Pop. (2007 est.) 294,608.