The Alb (also: Hauensteiner Alb) is a river in the southern Black Forest. It arises from two headwaters, the Menzenschwander Alb and Bernauer Alb, and flows in a southerly direction. It ends after (including Menzenschwander Alb) at a confluence with the High Rhine at Albbruck. Etymology The name Alb is possibly derived from a Proto-Indo-European word *albhos meaning "white" or perhaps "river". Headwaters The headwaters of the Menzenschwander Alb lie on the southern slope of the Feldberg mountain range in the Landkreis of Breisgau-Hochschwarzwald. The Bernauer Alb rises on the southern slope of the Herzogenhorn. The Menzenschwander Alb is about long and flows south-east past Menzenschwand. The Bernauer Alb is about long; it also flows south-east, past Bernau. The confluence of the two headwaters is at Glashofsäge, about from Sankt Blasien. The valleys of both headwaters were widened by glaciers during the ice age. Both are about high and dominated by grassland. The Bernau valley is a broad basin, characterized by moraines, marshy valleys, ravines, and Roche moutonnées. The hamlets and isolated farms that make up the valley lie some distance above the frost-prone valley floor. The glacial features in the Menzenschwand valley are even more striking. The Menzenschwander Kluse is a well-known terminal moraine. Below the Kluse, the Menzenschwand Alb plunges with several waterfalls through a small ravine to a basin created by the former Krunkelbach valley glacier. Middle reaches The area occupied by the municipality of Sankt Blasien's area is dominated by the classicist dome of Sankt Blasien's Cathedral. Below the village centre, the Alb form a waterfall, locally known as , after the Roman town of Tusculum. The Alb, like most rivers in this part of the Black Forest, then changes its course by about 60 degrees, towards the south. This is thought to be caused by tectonic movements of the Earth's crust, which have increased the gradient to the High Rhine. The only valley that continues in a south-eastern direction is about higher, in the saddle near Häusern. During the ice age, the Alb glacier was about high in this area, and its meltwater overflowed the Häusern saddle, into the Schwarza valley. Below this bend, the Alb water is collected in a reservoir, the Alb Basin. Its average surface area is ; it is impounded by a dam of about in length. Most of the water is piped to the Schwarzabruck reservoir. Both reservoirs are owned