The Alpine Rhine
Valley (German:
Alpenrheintal) is a glacial alpine valley, formed by the Alpine Rhine (German:
Alpenrhein [ˈalpm̩ʁaɪn] ), the part of the Rhine between the confluence of the Anterior Rhine and Posterior Rhine at Reichenau and Lake Constance. It covers three countries, with sections of the river demarcating the borders between Austria and Switzerland and between Liechtenstein and Switzerland. The valley is 93 km long. In the upper 9 km stretch, the valley width is 1.5 km with narrow (60 m) incised channel. For the next 71 km, the valley floor varies between 3 and 4 km; on approach to Lake Constance the valley widens up to 15 km.
Geography
The Alpine Rhine Valley is flanked by the Alps and its mountain ranges (especially
Alpstein 
, Plessuralpen, Rätikon Calanda, the
Albula Alps 
and the Glarner Alps), some higher than 3,000 m (9,800 ft).