Me and my buddy were of the first to summit Mt Superior this morning shortly after first light (7ish am). We skiied down the S ridge and perched ourselves on top of one of the east couloirs that leads into the main S face of Superior, hoping to drop in right away. Visibility was not letting up and after about 20-30 min we saw that it was looking a bit better into the Monte Christo couloir and we would have rock walls to help with in there. Having done it 4 times in the past and knowing the traverse off to the side to avoid the rappel in it, we agreed to drop into it. All was fine as we worked our way down skiing a couple hundred feet at a time. A couple leap frogs in (at about 10500ft), I traversed to the skiiers left just out of the main slide path and radioed to my partner to come down to me. He skiied down to me, but within seconds after doing so and I mean seconds after going just past me, slightly further to my left, he yelled in distress as he saw a powder cloud coming down towards us. I had a split second to process, my turned away from the slide, before I felt a thump of slough against my back and on the tail of my board. I didn't realize it at the time, but the slide was a lot bigger than I had registered. We must have just gotten the side of it as the main of it flushed down the couloir and towards the cliffs of the rappel. Somehow we were able to keep our footing and not get swept. We were certain someone dropped in on us and so we belined skiiers left traversing further to get into Monte Christo Gully and out of there asap.

I skiied down about 400ft after the traverse (I was leading), before I came to what I thought was just a choke onto the bottom apron, but then I realized it was another cliff. I told my partner I must have just missed another traverse over, so he descended looking for it but found nothing, stopping 50 ft short of me. We had traversed too far (it had been about 5 years since I last did Monte Christo Gully). We checked the maps and I realized that the traverse out of Monte Christo Directisimo and into MC Gully was just above the rappel station. The hastiness of the whole situation seems to have contributed to this mistake, though reviewing my gopro footage later today: moments before the slide and just before my partner got to me, I was apparently certain that we should have done the earlier traverse and vocally expressed it. No telling if we would have re-evaluated had the slide not come down, so a lesson in its own to be more sure of your route, especially if its been a few years on a given line. We transitioned, skinned back up (while hoping nothing else would come down), and then once back in the main couloir saw 2 other tracks going down, but no tracks lower down towards the road. We also looked up to see where the slide may have come down from. I noticed a little crown maybe 25 ft wide between the MC and Superior summits that had obviously slide along with a couple other small ones, possibly due to cornice fall, no tracks in that area. We figured that may have been the culprit of the slide, but we really had no idea for sure. Idid not notice any slide debris below the rap stations of MC direct from above, so my guess is though it had poured over the cliffs, it probably did not go much further.

From the 2 tracks we saw going down the main couloir, we knew that there was another party at the rap stations, so we descended towards them carefully, keeping an eye for the the traverse out, which we knew was just above the raps. We also made sure to only ski on the bed surface in the center of the couloir, so not to slough them. We saw them at the rap station, but communictation was hard with our 50-100 distance from them. Nonetheless we got assurance that they were clipped in and we could traverse on the untouched pocket of snow that would put us into MC gully. We really did not want to let any slough onto them. That went smooth without a hitch and we then quickly skiied down to the road within minutes, arriving down there at 9am. All in all it was one of the most stressful moments I've ever had in my 15 year backcountry career. We counted our luck/blessings and headed off to work for the day.

A few hours later, I reviewed the gopro footage and realized that the slide was almost certainly a natural due to cornice fall as it came barreling over the cliffs skiier right of the upper couloir. This can be seen in the included video, though I cut out the audio to keep our names anonymous. Winds though they had died down quite a bit in the morning as they were forecasted to, must have pushed the cornices to tether on their limits. That and potential winds slabs are why I had abandoned my original desire to go up white pine chute this morning. Needless to say, though we had planned to by down the route within 10 min had all gone according to plan, stuff can happen and one can get unluckly. In our case we were both unlucky and very lucky. We all tend to push it in the mountains, especially in the Wasatch and other popular mountain areas. We do it for that reward of great run after run and we try to mitigate risk. However, we get drawn into these false senses of security especially and complacencies when we and so many others go out, do something rad and come home day after day. We work on managing risk and I think as a whole we are much better at it than the population was 50 years ago largely due to amazing avlanche and mountain eduction resources. But we all still for the love of the thrill in the mountains, do push it, whether we like to admit it or not, or whether we are going to give it up or not. Anyways, rants and lessons aside, I feel as though I try to be aware of a lot of the dangers and make smart choices while still getting out there in the way I love. But this just goes to show that surprise accidents can still happen.