I find Mammoth works well for acclimatisation - specifically, as others have said, the Mammoth Mountain Lodge which is c. 9k ft vs the town at c. 8k ft. The extra 1k makes a significant difference; the blood oxygen saturation curve doesn't move much until 7-8k ft and then becomes increasingly steep, thus small changes in altitude have a significant effect on a) propensity for AMS, and b) acclimatisation.
I've driven from Reno, Vegas and LAX, and LAX is definitely the worst! However, from LAX you can fly to Mammoth Lakes airport and save 4-5 hrs drive.
