Gotthard Massif in the context of Oberalp Pass

The Reuss (Swiss Standard German: [ˈrɔʏs]; Swiss German: Rüüss) is a river in Switzerland. With a length of 164 kilometres (102 mi) and a drainage basin of 3,426 square kilometres (1,323 sq mi), it is the fourth largest river in Switzerland (after the Rhine, Aare and Rhône). The upper Reuss forms the main valley of the canton of Uri. The course of the lower Reuss runs from Lake Lucerne to the confluence with the Aare at Brugg and Windisch.

The Reuss is one of the four major rivers taking their source in the Gotthard region, along with the Rhine, Ticino and Rhône.

The river Ticino (/tɪˈtʃiːnoʊ/ tih-CHEE-noh, Italian: [tiˈtʃiːno]; Lombard: Tesin; French and German: Tessin; Latin: Ticīnus) is the most important perennial left-bank tributary of the Po. It has given its name to the Swiss canton through which its upper portion flows.

It is one of the four major rivers taking their source in the Gotthard region, along with the Rhône, Reuss and Rhine.The river rises in the Val Bedretto in Switzerland at the frontier between the cantons of Valais and Ticino right below the Nufenen Pass, is fed by the glaciers of the Alps and later flows through Lake Maggiore, which traverses the border to Italy. The Ticino joins the Po a few kilometres downstream (along the Ticino) from Pavia. It is about 248 kilometres (154 mi) long. The stretch of river between Lake Maggiore and the confluence in the Po is included in the Parco naturale lombardo della Valle del Ticino, a Nature reserve included by UNESCO in the World Network of Biosphere Reserves.