Yeah! My first camp in Aspen was in town, up a little hiking trail near a park. I found a tree with an already made pit beneath it, soft because squirrels had dropped twigs and pine cone litter there for years. I have a feeling that pit may have been a bear's hibernation spot. This was late April, so who knows? That being said, I spread my mat and sleeping bag in the pit, which was well-concealed by the lowest branches of the tree. Over the pit, I hung a camouflage poncho liner and a tarp. Both together held in a lot of warmth. There was no chance of hikers, joggers, or other characters finding this spot. I checked it out from several angles and it could not be seen from 6 feet away due to it being mostly underground. Why don't you come check out Durango? I've been here since before Halloween and it's much warmer and sunnier than Aspen and the high country. My biggest problem is: typical day camping in Aspen involves getting up at around 7 am, walking into town, working or shopping for groceries, a little time at the library to check email or charge devices, then return to camp....it's too chilly to read or do much of anything, so ya just have to get down inside your bag and go to sleep. even if it's early and the sun has just gone down...If you can dig yourself a lair, that would be great! There's a hillside across from the music school where you could squat for any length of time with an underground setup like you're talkin about. I scouted Aspen extensively to find an appropriate campsite. The city is surrounded by great potential places for what youre talking about. Of course there's always Difficult campground 5 miles east of town. In answer to your question, with enough paracord, tarps, and cardboard, you can do anything. And there are lots of nice rocks everywhere to build firepits or reinforce walls.