U.S. Census Bureau has just released American Community Survey (ACS) 2006-10 County-to-County Commuting Flows Products ACS 2006-10. Though regularly produced commuting data products address where people work and where people live, these flow products uniquely describe the residence to workplace relationship.
The following visualization will allow you to select a particular Utah county to see where resident workers work (out-commuters) and also where in-commuters live. The tables below the maps can be easily downloaded into excel by selecting the table, then placing your cursor over the export icon at the bottom of the visualization and selecting "crosstab." Full data sets can also be found at the Census website, by clicking here.