The Transfrontier Biosphere Reserve covers 3105 km2 (1,200 sq. miles), 1,800 km2 (695 sq. miles) in Germany and 1305 km2 (505 sq. miles) in France.

In 1999 it had a population of 237,000 approximately, 160,000 in Germany and slightly over 77,000 in France. The difference in population is not reflected in the number of municipalities as there were only 102 in the German part of the Reserve against 113 in France for a total of 215 in all.

The average population density of 76 inhabitants/km² is low for Western Europe, although it is higher on the German side (89 inhabitants/km²) than on the French (59 inhabitants/km²).

The bulk of the Reserve, 74% of the total area, is covered in forest including virtually the whole Vosges-Pfalz mountain zone. Given the extent of the natural areas, urban zones contribute only 5%.

The natural part of the Reserve, comprising the largest forest in Western Europe, has the lowest population density, with the result that most of the area has a rich and very varied natural heritage. Its cultural heritage is of much the same quality with 95 castles in the Biosphere Reserve, making it one of areas of Europe with the highest density of historical and related monuments.

Physical milieu