Gary, didn't you go to Colorado on vacations, and basically didn't have altitude issues either?? Staying at 5k surely helps.
Yeah, Steve, staying mostly in Colorado Springs, Aspen and Estes Park, all between 7K' and 8K'. Hit three fourteeners one trip and never felt anything less than great. It's so much easier there, though - once you're in the Rockies, even by road, you're constantly between 8,000 and 12,000 feet. Acclimation is almost an afterthough - you can't help but sleep high.
Denver and Boulder are the lowboys at 5200 feet - once you start heading west you go high quickly. Trail Ridge Road through RMNP hits 12K' (Visitor Center there - honest), as does a highway over Independence Pass. Just driving from place to place assists with acclimation.
