Hinterrhein (river)

Hinterrhein
The Hinterrhein southwest of Splügen
Native name	Rein Posteriur
Other name(s)	Posterior Rhine
Country	Switzerland, Italy (Valle di Lei)
Basin features
Main source	2,400 m (7,900 ft) 46°29′55″N 9°3′45″E / 46.49861°N 9.06250°E / 46.49861; 9.06250 (Hinterrhein source)
River mouth	585 m (1,919 ft) 46°49′24″N 9°24′28″E / 46.82333°N 9.40778°E / 46.82333; 9.40778 (Hinterrhein mouth)Coordinates: 46°49′24″N 9°24′28″E / 46.82333°N 9.40778°E / 46.82333; 9.40778 (Hinterrhein mouth)
Progression	Rhine → North Sea
River system	Rhine
Basin size	1,693 km2 (654 sq mi)
Tributaries	Right: Ragn da Ferrera, Albula/Alvra ...
Waterbodies	Sufner See
Physical characteristics
Length	64 km (40 mi)
Discharge	Average rate: 59.6 m3/s (2,100 cu ft/s)

The Hinterrhein (German; Romansh: Rein Posteriur; English: Posterior Rhine) is one of the two initial tributaries of the Rhine (less in length but bigger by volume) in the canton of Graubünden in Switzerland, flowing from the village Hinterrhein near the San Bernardino Pass through the Rheinwald valley into a gorge called Roflaschlucht. In this gorge an equally sized tributary, the Avers Rhine, adds waters from the deep Val Ferrera and the very remote alp Avers and its side valley Valle di Lei on Italian territory. After the Rofla Gorge, the valley widens into a section called Schams. The Hinterrhein then reaches Andeer, before passing through another gorge, Viamala just before Thusis. Now another tributary of slightly bigger volume reaches the Hinterrhein as the Landwasser, draining a system of valleys, which is commonly known as Davos joins via the Albula coming from the Albula Pass, which is also the name of a railway line that has become a UNESCO world heritage. Another big tributary of Albula river is Gelgia from the Julier pass area. After flowing to Rothenbrunnen through a valley called Domleschg with an incredible number of castles (showing the importance of transit in the area) again the river is left alone from civilisation in the floodplain Isla Bella near Rhäzüns, before it joins the Anterior Rhine at Reichenau, all of them also in Graubünden.