Hesse in the 1940s received more than a million displaced ethnic Germans. Due to its proximity to the Inner German border, Hesse became an important location of NATO installations in the 1950s, especially military bases of the US V Corps and United States Army Europe. The first elected minister president of Hesse was Christian Stock, followed by Georg-August Zinn (both Social Democrats). The German Social Democrats gained an absolute majority in 1962 and pursued progressive policies with the so-called . The CDU gained a relative majority in the 1974 elections, but the Social Democrats continued to govern in a coalition with the FDP. Hesse was first governed by the CDU under Walter Wallmann during 1987–1991, replaced by a SPD-Greens coalition under Hans Eichel during 1991–1999. From 1999, Hesse was governed by the CDU under Roland Koch (retired 2010) and Volker Bouffier (incumbent as of 2020). Frankfurt during the 1960s to 1990s developed into one of the major cities of West Germany. As of 2016, 12% of the total population of Hesse lived in the city of Frankfurt. Geography Situated in west-central Germany, the state of Hesse borders the German states of Lower Saxony, Thuringia, Bavaria, Baden-Württemberg, Rhineland-Palatinate, and North Rhine-Westphalia (starting in the north and proceeding clockwise). Most of the population of Hesse lives in the southern part, in the Rhine Main Area. The principal cities of the area include Frankfurt am Main, Wiesbaden, Darmstadt, Offenbach, Hanau, Giessen, Wetzlar, and Limburg. Other major towns in Hesse are Fulda in the east, and Kassel and Marburg an der Lahn in the north. The densely populated Rhine-Main region is much better developed than the rural areas in the middle and northern parts of Hesse. The most important rivers in Hesse are the Fulda and Eder in the north, the Lahn in the central part of Hesse, and the Main and Rhine in the south. The countryside is hilly and the numerous mountain ranges include the Rhön, the Westerwald, the Taunus, the Vogelsberg, the Knüll and the Spessart. The Rhine borders Hesse on the southwest without running through the state. Only one oxbow lake—the so-called Stockstadt-Erfelder Altrhein—runs through Hesse. The mountain range between the rivers Main and the Neckar is called the Odenwald. The plain between the rivers Main, Rhine, and Neckar, and the Odenwald Mountains is called the Ried. Hesse is the greenest state in Germany, as forest covers 42% of the