Climbed the right hand Underhill Couloir twice. First time with Miguel Carmona in the early 1980s. We left the Gailey Morraine camp at 9 am, were on the summit at noon and back in camp at 2 PM.
Second time with my wife Penelope on August 8, 2004. Found the register at the bottom of the summit pinnacle, boo! We third classed the moves (good climbing), great summit. Did three raps down the extremely loose couloir. I would not climb this again when not covered by snow. The gully was really dangerous. On our second rap, some boulders not only severed our rope in half, but injured my leg a bit. Very slow going down after this, we ran out of daylight just above the schrund, bivied there. Early next morning scrambled down the schrund and to camp, packed up and down to car.
P.S. I just remembered that Bryan Johnson and I climbed the right couloir in May of 1994 testing ice tools for our Nepal trip later that year.
Started my short Palisade traverse by going up the Right Underhill. It was fairly soft snow to the chockstone and a lot of sticking to the rock on the right wall after.
Climbed with El Greco during SMG outing - awesome mountain and fun route.
Ascended the right hand Underhill couloir. Bergschrund was passable by end running it - a few more cracks present around it too. The slope angle in the couloir was up to 50 or so degrees in places. We passed the chockstone on the left with an awkward move. A pitch of rock at the end of couloir puts you on the summit ridge, where 3rd class and exposed 4th/low 5th climbing leads you to a short, easy but very exposed traverse to the base of the summit block. Lassoed and free-climbed the summit block - a lot of fun (a short bouldering problem, essentially)!
Got off route and climbed the left hand side of Underhill to the top, then traversed the ridge tog et back on route. We hadn't studied the topo well enough and climbed the first pinnacle above the slabs. By the time we reached the top and realized it was the not the summit we had run out of time.