Go to the Colorado DOW's web site, you will find out what leftover tags are available. It will say as well if they are private land only tags or public lands. There are a lot of leftover tags available in the Craig Meeker area as that is the largest concentration of elk in the State.
I hunted the Craig and Meeker area last year, doubt I'll ever do it again. Too many hunters, I was always running into orange, the elk were not comming buy so decided to move and couldn't go 100 yards in any direction and not run into another hunter. I probably would have filled my tags though if there hadn't been some other problems with that hunt as well, and had to come down out of the mountains due to an injury in the hunting party.