The Valais is the third-largest canton of Switzerland covering 2016 square miles of which only 1107 are productive. It is also a world of its own: it received its name "the valley" from the 100 mile long valley of the Rhone River which has its source above the small town of Gletsch below the highest point of the Furka pass. This main valley is flanked on the north and south side by many of the highest peaks of the Swiss Alps. The northern side toward the Canton of Bern is forbiddingly steep, and the Lotschental and the valley leading to the Leukerbad are the only valleys which branch off on this side while many long and deep valleys branch off on the southern side, e.g. the Mattertal with Zermatt, the Saastal with Saas Fee, the Val d' Anniviers, the Val d'Herense, the Val de Bagnes, the Val d'Entremonts leading to the Grand Saint-Bernard Pass. Because of these formidable mountain ranges, the only open access to the canton is at its westernmost point toward the Lake of Geneva, and even there one has to pass through a narrow gate at Saint-Maurice to enter the main part of the Valais. All the other routes to the canton must cross mountain passes: the Furka and Grimsel from the east, the Nufenen, Simplon, Grand Saint-Bernard and Col de Forclaz from the south, and the only access from the north are from Aigle over the Col des Mosses and the Col du Pillon and through the Lotschberg tunnel and the Lotschental.
"The Imeschs from the Upper Valais - Glimpses of a Swiss and North-American Family,"
Swiss American Historical Society Review: Vol. 42
, Article 3.
Available at: https://scholarsarchive.byu.edu/sahs_review/vol42/iss1/3