original: The mountain range forms the border between both countries for 150 kilometers, extending from the western border of Saxony to the Elbe river.
simplifications: The mountain range forms the western border of Saxony to the Elbe river for 150 kilometers. The mountains form the border between the two countries for 150 kilometers. For 150 kilometers the mountain range forms the border between countries, from the west of Saxony to Elbe river. The mountain range creates the border between both countries for 150 kilometers. It extends from the western border of Saxony to the Elbe river. The mountain range forms the border between both countries for 150 kilometers. It goes from the western border of Saxony to the Elbe river. The mountains separate the two countries for 150 kilometers. The mountains are the border between the countries for 150 kilometers. The mountains form a divide from both countries for 150 km, starting from the west border of Saxony to the Elbe river. The mountain range border extends for 150 kilometers from the western border of Saxony to the Elbe river. The mountain range forms the border between the two countries for 150 kilometers, reaching from the western border of Saxony to the River Elbe.