The east coast is not the only place in the country with beautiful fall colors. California has a litle mountain range called the Sierra Nevadas that provides abundant locations to see nature prepare for winter.
Highway 395, which stretches the lenght of the Owens Valley on the eastern side of the Sierras is a great starting point. Keep in mind that if you going to travel to the western side of the Sierras many of the roads leading there are closed after the first fall snows (as of October 12, 2010, The Tioga Pass in Yosemite is closed for the winter).
Mono lake, Bishop, June Lake all provide spectacular fall scenery for the west cost bound traveler.