The equation that seems to work for me is:
Get a Trails Illustrated map that covers one or more major streams that have decent sized tributaries, that come down from wilderness areas (Eagles Nest, Rawah, Flattops, Maroon Bells, Wemuniche, South San Juan, Lizard head...http://www.coloradowilderness.com/wildpages/map.html
Find a trail that takes you 1-2+ miles away from the nearest road, travels into the wilderness area and crosses a stream around 9000'+. Start fishing. Use a #14 -16 Stimulator, EHC, Royal Wulff or other type of attractor and prepare to be amazed.
A personal favorite of mine is the Three Forks area above Platoro Reservoir on the Conejos River. Its an easy 3 mile hike to any of three streams up into the Wemuniche wilderness area.
If you are serious about fishing out there, I would recommend getting the book, "Flyfishing in Southern Colorado" to get a lay of the land (and major Streams) and then start charting out the tributaries they don't talk much about that come out of the wilderness areas. The author says in the book that he specifically left out many of the better small streams for fear they would get overfished. And I won't name names here either because finding those streams are half the funl (including one that I'm going to visit this year thats on the back-end of a 5 mile hike to a spot someone else lost a camera on...)
Even if you don't find 14-16" Cutts in every run, most streams that fit those criteria are full of 10-12" Brookies and Cutts (if they are decent sized tributaries - think LR above Elkmont)...