the right model for the rockies (and cascades and sierras) is to be found in Switzerland/Austria/France/Germany near the high Alps. In the long run it's not going be urban development all the way up to the summits, but I would expect the Rockies to have more of the same sort of human presence that the Alps do in about 1-200 years time. The big difference is precipitation ... the Rockies are on the low side compared to the Alps, and that may take things in a very different direction.

I'm not so sure. People like to be around other people, and like minded people. Sure, some will go to really out of the way places, but I'm not so sure about how many will stay, long term.