For a true mountaineering adventure, climb the East Couloir on the East Face of remote Mt. Jackson in the Holy Cross Wilderness. This peak is 13,670 feet and one of Colorado's top 200 peaks. We backpacked in Saturday on the Cross Creek Trail from Tigwon Road about 9 miles (gate to trailhead was closed adding an extra mile) and camped by Cross Creek almost at the large man-made bridge at 9,880'. Up and down good trail (you do about 2,000' while gaining about 1,300') many creek crossings, ski poles helpful. Sunday morning set off to find the couloir with the topo and "Green Book" (couloir not in Green Book). Guessed that the couloir might be the gully to the north of the rock outcropping shown on the topo under the word "Jackson." From Green Book directions, started close to the bridge at 9,880' and bushwhacked up steep tree and rock slope to 10,800'. Found trail that contoured to the southwest to marshy area at 11,000'. From there, you can see several couloirs on East Face but beginnings obscured by prominent vertical cliffs. Ascending northwest traverse through timber and grass-rock benches brought us to Lake at 11,600'. Could see top of what we thought was eastern-most couloir to summit but still could not see bottom - view of most of couloir still completely blocked by cliffs. Decided to attain top of cliffs by heading toward Northwest Cirque and then doubling back at top of cliff band to hopefully end up at couloir. This took awhile going up snow (with crampons) and rock slopes. Couloir was not immediately evident without substantial contouring to the south at approximately 12,600'. We finally saw it and found place to drop down off of some ledges about < or so of the way up the couloir. Put on crampons and went up about 800' to 1,000' on fairly good snow, slightly mushy. Got to within 200' of the summit where it melted out. Did not use a rope, couloir narrow in spots. We judged it to be a combination of Dead Dog and Skywalker in steepness. (In talking to Paul Svetlik afterwards, who we found out pioneered this route for CMC in 1970s, he said that couloir was 50 degrees consistently, middle part 60, and 55 near the top - he has had to use ice-screws and rope at times.) Walked to summit. From there you could glissade back down the Cirque unless you are with an obsessed partner who must go over to Unnamed 13,433', a "ranked" peak reached by an easy = mile traverse across a saddle to the other summit. From there we glissaded down the northeast scree slopes of 13,433 to the valley floor (glissading down the nearby steep snow slope looked dangerous and close to rocks) and made our way back to the Lake along the entire East Face of Mt. Jackson, passing several east-facing couloirs, and finally seeing the bottom of ours, the eastern-most one at the mouth of the valley. By this circle route we figured out that you could go southwest from the Lake to the start of our couloir, which would still be over arduous terrain but more direct. Making our way back to camp in the rain at 10:00 o'clock that night was unfun. After 14 hours of rough terrain our bodies decided that sleep was necessary even though we were expected home that night. So, after an extra night we backpacked out Monday, called home, and went and ate lunch in Minturn. This is truly a great trip and an especially rewarding alternative to what can be merely a long slog up a top 200 peak.