I can buy more people are moving into Utah than out - but it's probably well below the total of most of the other fastest growing states. You can dismiss this study, but even the state demographer said most of the growth is driven, largely, by the birth rate:
http://www.heraldextra.com/news/local/ce...8dddcc8-b692-5973-8bcf-da7a4e77165e.html
She estimates the state added about 10,000 people due to migration - which is dramatically lower than what it used to be (25,000 to 30,000 each year).
So, Utah continues to see a bulk of its growth through localized means. To contrast, Colorado, between 2009 and 2010, saw 200,000 people move into the state:
http://www.denverpost.com/ci_18121789
Obviously, Colorado will have a bigger number, because it's a bigger state, but Denver, which is
smaller than the state of Utah by a large amount (Denver's population is 634,265) saw an increase of 21,436 new residents from other states - about 10,000 more people than the entire state (pop. 2,900,872) saw last year. That's a huge contrast which further proves the point - Salt Lake, and Utah, lags behind in outsiders moving into the state.
Which, to many, will be a good thing. Of course, when a bulk of your population growth comes from people who haven't even learned to walk yet, well...