Transcription: You're there, in the southwestern corner of the United States. The four deserts of the southwest are sandwiched between two great mountain ranges, the Rocky Mountains to the east and the Sierra Nevada to the west. But on this scale the map gives a false impression. In reality the mountains are separated by plains, plateaus and gentle slopes, and it's on these that the deserts were formed barely 10,000 years ago. Select the red spot to have a closer look. you
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