Based on Wikipedia info, the following high-rise buildings in the Greater Las Vegas area would seem to be eligible: Palazzo (642 ft), Encore (631 ft), Trump Int'l (622 ft), Wynn (644 ft), Cosmopolitan (610 ft), Aria (600 ft), Elara (600 ft), Vdara (570 ft), Waldorf (560 ft), New York - New York (529 ft), Palms (517 ft), Martin (513 ft), Bellagio (508 ft), Sky LV (500 ft).
With these, it seems like Nevada should make the list.
With these, it seems like Nevada should make the list.