Vorderrhein

Vorderrhein Anterior Rhine
The Vorderrhein in the Ruinaulta gorge
Area of the Alpine Rhine with its headwaters
Native name	Rein Anteriur (Sursilvan) Ragn Anteriur (Sutsilvan) Rain Anteriur (Rumantsch Grischun) Vorderrhein (German)
Location
Country	Switzerland
Canton	Grisons
Physical characteristics
Source
• location	Lai Urlaun
• coordinates	46°37′34″N 8°41′04″E / 46.62611°N 8.68444°E / 46.62611; 8.68444
Mouth
• location	Reichenau
• coordinates	46°49′24″N 9°24′28″E / 46.82333°N 9.40778°E / 46.82333; 9.40778
• elevation	585 m (1,919 ft)
Length	76 km (47 mi)
Basin size	1,512 km2 (584 sq mi)
Discharge
• average	53.8 m3/s (1,900 cu ft/s)
Basin features
Progression	Rhine→ North Sea
Tributaries
• left	Aua da Russein, Flem, Schmuèr, Ual da Mulin
• right	Glenner, Rabiusa, Rein da Curnera, Rein da Medel, Rein da Nalps, Rein da Sumvitg

The Vorderrhein (German: [ˈfɔʁdɐˌʁaɪn] ^ⓘ; Sursilvan: Rein Anteriur^ⓘ; Sutsilvan: Ragn Anteriur; Rumantsch Grischun, Vallader, and Puter: Rain Anteriur; Surmiran: Ragn anteriour), or Anterior Rhine, is the left of the two initial tributaries of the River Rhine (the other being the Hinterrhein). It is longer than the Hinterrhein, but has a lower discharge than the latter at their confluence, which marks the beginning of the Alpine Rhine section.

The Vorderrhein and nearly all of its tributaries are located in the Swiss canton of Grisons (Graubünden), with the largest communities along the river being Disentis and Ilanz. One of its upper tributaries, the Rein da Medel, rises in the canton of Ticino.

Vorderrhein was also the name of a judicial district that was created in 1851 with the reorganization of the judiciary of Graubünden. In 2001, it was annexed by the District Surselva.