From the trailhead for Middle Fork Cimarron, walk south up the trail for the two plus miles to the crossing of the creek coming out of Porphyry Basin. Locate a well used trail on the north side of the creek that leads into the upper Porphyry Basin. This trail begins by climbing steeply for a short while, then more gradually as it makes a very long switchback to the north before turning south and bringing you back to the drainage at about the 11,200 ft. contour. Then the trail climbs more gently, coming to a fork in the drainage at 11,400 ft. Across the creek to the south and up on a hillside is a small cabin that appeared to be in use back in 2005. We walked over to it and investigated a little before crossing back over the creek and heading on up valley. Shortly above the cabin, the valley opens up and you'll leave the last trees. This upper basin stretches for about a mile. It is a beautiful, tundra filled basin that earlier in the season would be rife with wildflowers. The most interesting thing we saw in this basin was one lone buck who spotting us, tore off back down the valley and never stopped until he was out of our site.
As the basin gradually turns more easterly, begin veering south, heading for a saddle between the east and west summits of UN 13,340. This elevation is an interpolated one. The east summit shows an elevation on the survey map of 13,315 ft. The west summit has no elevation on the map, but the contours indicate it must be at least 13,320 ft. As we headed for the saddle, we were able to follow some tundra for a while, but eventually had to enter the shallow gully and begin scrambling up the scree and dirt on poor footing. We had to negotiate about 600 vertical feet of this stuff and as we approached the saddle, it became very difficult to maintain footing. At the saddle, a difficult section along the ridge compelled us to contour on the north side through the head of another steep gully and climb further up. This last scramble up was even worse for footing, requiring us a couple of times to use our ice axes plunged into the dirt to secure our feet. But once on the ridge again, it was easy walking on up to the summit and only required a few more minutes. The summit is composed of a lot of large, flat, brittle rocks and there was a cairn. To the south, you can clearly see El Punto. From this summit over to it would be an easy walk, but it appeared that gaining the summit from the north side would be a difficult feat. Adding UN13,340 to an El Punto day would be easier than coming up Porphyry Basin as our route has you do.
Descend as you came (on the scree this would be a fast one) or consider contouring over and bagging UN13,222 as well. It would make little sense to leave that one hanging, but it won't be easy.
Links to other information, routes & trip reports for this peak that may be helpful.