I'm not certain what that is exactly, but i believe it is a bird. Probably some sort of owl. Try a birding website to get the exact species. The repetitive nature I heard and you described does not sound like elk. If it were some sort of small mammal, like a squirrel it would not continue all night. So like I said, best guess is its an owl.
UPDATE-because I'm a geek and it was eating at me- I'd now say it is a northern pygmy owl, given your location and the owl calls I was just listening to.
Every year many hunters and outdoorsman and women come out west from the midwest and east coast to hunt the prized mulies and elk. One topic that comes up often is altitude sickness. My advice for flatlanders is to get into the best possible shape. Start months before your hunt, usually really ramping up my cardio around March or April.
I run 5-10 miles 3 times a week, and also go for walks carrying my pack with about 50lbs to simulate what could be on my back. Another useful tip is to drink A...