Mammoth Mountain: 11,059 ft at the summit, 7,953 feet at the base. I have snowboarded on the mountain but I didn't go to the very top-- Was just a beginner. So I will said I have been to 9,000 something.... 
It is all way north in California, two hours south of Lake Tahoe.
Palomar Mountain in San Diego County (where the famous observatory is at) is 6,000ft high... I went up there for a night sightsee for the stars but it was cloudy and they showed us a slideshow of different stars instead. Blah.
Malfoyish-- Lake Placid in New York has the summit elevation of 4,650' but the base is 1,220 feet... Not sure if I got the location right because there is another Lake Placid in Florida. 
