There has been an influx of people from throughout the US, combined with institutional funds that invest in single family homes and other residential development and are more active than I like. I wish munis would have more 'owner occupied' rules to squeeze out the institutional investor possibilities.
Two very successful real estate agents I know that operate in the northern Utah County and southern SL County areas have told me they've dealt more with buyers from the northeast, mid-west, mid-atlantic and south than those coming from the west coast.