The Black Forest consists of a cover of sandstone on top of a core of gneiss and granites. Formerly it shared tectonic evolution with the nearby Vosges Mountains. Later during the Middle Eocene a rifting period affected the area and caused formation of the Rhine graben. During the last glacial period of the Würm glaciation, the Black Forest was covered by glaciers; several tarns (or lakes) such as the Mummelsee are remains of this period.
Rivers in the Black Forest include the Danube (which originates in the Black Forest as the confluence of the Brigach and Breg rivers), the Enz, the Kinzig, the Murg, the Nagold, the Neckar, the Rench, and the Wiese. The Black Forest occupies part of the continental divide between the Atlantic Ocean drainage basin (drained by the Rhine) and the Black Sea drainage basin (drained by the Danube).
Administratively, the Black Forest belongs completely to the state of Baden-Württemberg and comprises the city of Pforzheim as well as the following districts (Kreise). In the north: Enz, Rastatt and Calw; in the middle: Freudenstadt, Ortenaukreis and Rottweil; in the south: Emmendingen, Schwarzwald-Baar, Breisgau-Hochschwarzwald, Lörrach and Waldshut.
The forest mostly consists of pines and firs, some of which are grown in commercial monoculture. Similar to other forested regions, the Black Forest has had areas that were annihilated by mass logging. Due to logging and land use changes the forest proper is only a fraction of its original size. The cyclone Lothar downed trees on hundreds of acres of mountaintops in 1999. This left some of the high peaks and scenic hills bare, with only primary growth shrubs and young fir trees.
The main industry is tourism. In addition to the towns and monuments noted below, the Black Forest is crossed by numerous long distance footpaths, including some of the first to be established. The European long-distance path E1 crosses the Black Forest following the routes of some of the local long-distance paths. There are numerous shorter paths suitable for day walks, as well as mountain biking and cross-country skiing trails. The total network of tracks amounts to around 23,000 kilometres (14,000 mi), and is maintained and overseen by a voluntary body, the Schwarzwaldverein(Black Forest Society), which has around 90,000 members (figures from Bremke, 1999, p. 9).
Black Forest clockmakers are renowned for their precision clocks. Most of the mechanical clocks are now sold as antiquities as many factories were shut down after the First World War and the Second World War. A few factories survived the structural change.
There are many historic towns in the Black Forest. Popular tourist destinations include Freiburg, Calw (the birth town of Hermann Hesse), Gengenbach, Staufen, Schiltach, Haslach and Altensteig. Other popular destinations include such mountains as the Feldberg, the Belchen, the Kandel, and the Schauinsland; the Titisee and Schluchsee lakes; the All Saints Waterfalls; the Triberg Waterfalls, not the highest, but the most famous waterfalls in Germany; and the gorge of the River Wutach.