I don't know much about calling in CO as far as places to go. Be ready for lots of dry stands and boring time sitting in the snow making noise. When you find a good area, the action can be fast and frequent though!
Here's the things I focus on:
1. You don't have to hike a long ways from the the truck. Over a small rise is plenty.
2. Never, ever call for more than 20 minutes. I never go over 15, and never over 10 at night.
3. With the other two, call 15-20 stands per day. You're trying to call to as many uneducated, responsive dogs as possible in a day.
4. Carry a rifle AND a shotgun. Plain #4 Buck will do fine, through about a .690-710 choke. Pattern it first if you are really into it. Any rifle will work, but have shooting sticks at least. I like my gun locked into a tripod for coyotes. Keep the shotgun in your lap; if they hang up you'll have plenty of time to transfer to the rifle.
5. Let them come! Don't move whatsoever unless they stop and appear to be ready to leave, you're sure they're hung up, or they're right in your lap in shotgun range.
6. Any call will work. My philosophy is to keep things simple. Simple rabbit distress will bring in just about anything willing to respond. I only ever howl if they are howling at the call (usually means they know what's going on). I like Carver custom calls, but anything will do. I use rabbit distress, rodent distress, and pup distress most often.
7. An elevated position will help a lot, but I like to keep the bottom of the hill in shotgun range.
8. If it's windy, use a LOUD call. Sound doesn't travel well in bad wind. In calm conditions, a low-medium volume rabbit distress will bring them in from over a mile (terrain dependent).
Good luck man, it's way addicting! Before you know it you'll have a whole new set of gear just for predator calling, night gear and all. Have fun and post pics.
