I respect Jeffs knowledge and accomplishments, I think many know that him and Priti have accomplished quite a lot and, presumably, know what they are talking about - but I strongly disagree with this post and think it could be somewhat dangerous to leave it here for people who are looking for info on the route.
I actually just solo'd Triple Couloirs two days ago, and I saw this comment before I went and already disagreed with it, but now that I have been up the route I can speak from experience.
For reference on my background, for about 5 years ice climbing has been my main interest and I typically spend every winter in Hyalite. In Hyalite my limit is usually WI6. I also recently climbed the Polish Route on Colfax. I also come from a mountaineering background before that, and work as a guide on some of the volcanoes and have many years of experience using and teaching self arrest techniques.
I arrived at the base of the runnels, and there appeared to be a thin smear of ice that appeared to lead to where I should be able to safely get into the second couloir. I started up them and eventually ended up somewhere that was not visible from the base of the runnels, and the ice disappeared. I relied on small thin patches of consolidated snow and blank rock to finish the section which was not terribly hard but quite insecure and low percentage holds. After this came another section that was steeper, and fortunately had just enough ice in it to get up, using very delicate thin technique, but had those few marginal patches of ice not been there I would have been a little screwed. Several times while soloing the technical section I looked down and thought about Jeffs comment that a fall would not be high up enough to result in fatality or injury, and you could self arrest... by the top of the runnels where the climbing got insecure I could only laugh at the thought of hitting the snow safely and self arresting. I think my head would have tomahawk bashed into the rock that creates the corner system about 6 times and who knows where my body would have landed.
That said, I did have fun and probably would solo it again, but be warned that even if you carry bail gear theres almost no opportunity for pro in between pre existing anchors, so youll have to make it to one before you could bail down if the route is out. The rock that is under the ice is quite blank and makes dry tooling it to get to your next patch of climbable terrain pretty insecure.
Also, I see that Jeff posted that in 2022, not sure the last time he climbed it but I know 2016/2017/2019 the route used to come in very fat, and Jeff may referencing times when the route used to see conditions that made it a much more secure feeling climb, and perhaps what you saw at the base of the runnels continued consistently throughout. Also, I think back then the Couloirs tended to be a bit more neve, where both times I've been in the route it seems to be more soft snow filled which would be futile to self arrest.
Just wanted to add this to balance out the perspective.
