This past year myself and my hunting partner hunted up in northern Colorado near Walden. Opening day we were back in camp and relaxed by 8:30am. My buddy got a nice 5X5. For myself we went over to Kremmling, middle park area. We went with a spot and stalk hunt, it's so open just grab the binocs and glass away. We spotted this monster mule deer out in the sage brush, all we could see were antlers. We put a stalk on him and got within about 200 yards when he decided to stand up. He's a 6x6 with about a 25 inch spread, 325 field dressed. He should score around 190. We have taken 3 nice deer out of that same spot.
As for eastern Colorado most of it is private and there are more whitetales than mules, but they are huge from what I understand. Let me know what you decide