Mount Richthofen, at 12,951 (or 12,940 depending who ya ask) feet, is the summit of the rugged and forbiddingly named Never Summer Range. The peak is on the boundary of Rocky Mountain National Park and the Colorado State Forest, as well as Jackson and Grand Counties. As per Brian Kalet, Richthofen may be the high point of Jackson County. Richthofen is surrounded by other ranges on all four sides, and aside from the nearby highway has a remote mountain feel compared to much of the Front Range. It can be accessed year round and presents a variety of mountaineering challenges, from hiking and scrambling to ski mountaineering and snow climbing. Not only is this mountain not a tourist death trap 14er, but it is just barely not an increasingly popular 13er, so you might have some semblance of solitude even on a summer weekend. In the winter, with much longer approaches, this mountain is stark and wild.
For the E side of the mountain, start from the Colorado River Trailhead off of Trail Ridge Road between Grand Lake and Milner Pass on the western half of the continental divide in Rocky Mountain National Park (RMNP).
From the W, to access the W and SW sides of the mountain, it appears from the map that one could approach via CO Rd 21/FS Rd 740, but you would have to find out whether the mountain is accessible from there on your own.
Parking at the Lake Agnes Trailhead in the Colorado State Forest requires a $5.00 day use fee as of 2012. These things change, and they never get cheaper.
From the east side, one must enter RMNP, I would assume the standard park entrance fee applies.
All state and federal laws are in effect, just in case you were wondering. Since this is Colorado, and I am writing this in 2013, that means you can smoke pot up there I guess.
For camping in Rocky Mountain National Park, check the NPS website.