Don't underestimate this hike/ski; it is very strenuous. Bring plenty of food & water. Don't forget your sunscreen! (I came back with my head looking like a tomato.) And have a plan for your exit, and a back-up plan, etc.
Also note that if conditions don't look good avalanche-wise or otherwise, it's not easy to abort a ski descent of Session's Peak once you've reached it. Going back along the arduous ridge might be the best abort option, but you won't look forward to it after now knowing just how hard it was.
What I'm calling Sessions's Peak here is a prominent peak along a ridge line that forms the Session's mountain range. The ascent shown is just one possible approach. An alternative, for example, may be to go up the gas pipeline starting in Mueller Park Canyon.
Anyhow, the approach I took was to start at Holbrook Canyon Trailhead. Doing so, look for a switchback that takes you to the south side of the canyon. It's a steep trail, but not too bad. Eventually it connects up to an old jeep road. Not long following this, you'll come across an old Christmas Tree farm. (I wish I knew the history of it.)
Keep following the road up the mountain until you find the gas pipeline crossing. (It's covered in snow, yes, but in spring it may be easier to realize you're there.) Keep skinning up the ridge until you reach an over-look of Rocky Drainage on its west side. This will be your first view of the prized line, Session's Peak Run
, coming down from the summit on the east side of the drainage.
This is where things get tough! The ridge line between the west over-look and the east summit gets quite difficult in places, and it can be extremely corniced. An ice axe and crampons will be essential here. The difficulty of the ridge is compounded by the need to carry your skis on your pack. Take your time and be careful! I recall the need to circumvent a few pinnacles by traversing some steep snow slopes, then regain the ridge proper. Stay well back from huge cornice structures.
Once at the peak, you're ready to ski into Rocky Drainage in style! Beware, however, not only of the potential avalanche danger, but also of a need to have some sort of plan for getting out. You're going to lose a ton of altitude, and none of that goes toward helping you get home if your plan is to return the way you came. What I did is ascend the other side of the drainage to link back up with my old skin track, but this is very conditions-permitting. Alternatively, you might ski down the drainage and connect up with the Kenny Creek Trail, but it is very hard to follow.
If you do regain Session's ridge, don't make the mistake I did of losing the trail you came up. I ended up bushwhacking to the bottom of Holbrook Canyon, then taking the Holbrook Canyon Trail out. It was very unpleasant, to say the least.