I grew up in a small town in MT, moved to the east coast after college, lived there for 8 long years. I would go back to MT and make trips to CO to hunt every fall for a week or two. I found myself planning my life around those trips. I managed to find outdoor things to do, but it was no where near what I had in MT.
I've spent a fair amount of time in Denver, not lived there, but used visit often for weeks at a time, and am down there for work occasionally. Its a big city, but also has a lot of open space, and the mountains are only an hour drive from about anywhere. I could think of much worse places to live, and many far better. That said I would never chose to live there, no amount of money, and no amount of coercion would convince me to live in a large metro area again.
That said, after moving to Alaska 9 years ago, the only place on the list other than here was MT and WY, and I don't think I'll ever move back to MT. I've thought long and hard about it the last year or so, but I just can't chose a place that offers me anything better than what I currently have here. I drove through more open space/public land yesterday than there is in half of Montana, just to go fishing.
One thing I learned long ago, if you can find a job, you can find the one you want where you really want to live if you look hard enough.