Very interesting, I have lived in Boulder for years and can attest that it is a wonderful area (not just Boulder the entire Denver/Boulder/Colorado Springs front range is beautiful) that is noticeably growing. It is also palpable, just anecdotally, that people who talk about moving almost entirely talk about northern California, Portland, and Seattle. If not the northwest, then Austin. Very cool to see these anecdotes confirmed by statistics.
Deschutes County, OR (Bend, basically): Californication.
Boulder, County, CO: a lot of people are going there, but those who leave appear headed for the pacific northwest.
Maricopa, County, AZ (Phoenix): wow... that's a lot of people.