The CNN map shows the counties for each candidate. So far, Santorum is strong in the east and south, Romney in the metro area and the north. Nothing from the west along the UT border yet.
The western slope (the western part of Colorado) is most conservative (aside from a few more liberal spots, such as Aspen, Steamboat Springs). Most liberal is Denver, where it would be expected that Romney would take that. Colorado Springs is most conservative probably in state.
I lived in Colorado for 11 years (from 1992 to 2002 and then again this past year); Western Slope has changed in that time, vastly. Increased numbers of Californians (more liberal) have flooded the state and really has altered it completely....so it’s becoming less conservative as a whole. (But still way more conservative generally speaking than California and New Mexico).