Fossil Mountain & The Ice Cave Couloir – Waist Deep November Pow & The State of the Teton Snowpack (Nov. 2021)

Fossil Mountain is a remote 10,921 foot peak located deep in the central Teton Range. The Ice Cave Couloir is a short, steep and seldom skied couloir that will only be relevant to enthusiasts of the obscure. While hardly worthy of its’ own mission, the “Ice Cave” made a great addition to Carl Osterburg and I’s first alpine mission of the 2021/22 season.

In addition to the story of our successful November soul quest, a summary of our snowpack observations from one snow pit and time spent on three different 10,000+ foot aspects will be detailed at the bottom.

Fossil Mountain from the west, basking in golden dawn light.


October and November have brought a slow but steady “Teton trickle” of snow. The year started with a multi-foot blasting, followed by unseasonably warm and dry conditions. A myriad of light dustings saw us into mid-November when a cold front rolled through with substantial precipitation. Almost overnight, one to two feet of snow blanketed an otherwise sparsely protected landscape of bushes and rocks. Grand Targhee claimed a total recorded 21/22 snowfall of eighty three inches. After hearing too many reports of decent turns, I finally clicked into skis on November 20th. Three Teton Pass laps revealed a shallow but “deep enough” and sturdy snowpack, and excellent turns were shared on Olympic and Thanksgiving Bowl with my girlfriend. Immediately my brain switched into alpine mode, and dreams of the steep and spicy took hold. One phone call to my trusty lover of arduous approaches, Carl Osterburg, was all it took. On the morning of the 21st we were off with headlamps into the depths of Darby Canyon, gunning for powder and adventure on one of my favorite Teton sleeping giants, Fossil Mountain.

Carl skinning through the upper Darby meadows

Fossil Mountain – South Face

The morning was far colder than we anticipated, with temperatures in the single digits as we climbed into the exposed meadows of Darby Canyon’s North Fork. We had been on skins for over three miles and were just starting to emerge from the dense forest. Luckily we got to start at the summer trail-head which substantially chopped our approach – you never know the hand forest service roads are holding. Six inches down low turned twelve as we climbed past 9,000 feet, becoming deeper with every increasing notch of altitude. For those unfamiliar with ski mountaineering from the Tetons west, approaches are very long and often involve lots of time spent crossing rivers, meandering through shubbery and other lowland foolery. For this reason, peaks of the west are skied exponentially less than those of Grand Teton National Park. However, for motivated folk who don’t mind a little extra effort, the west side provides phenomenal skiing on reliably untracked slopes.

As we reached the saddle separating Fossil from a small unnamed highpoint to the south, the wind picked up serious steam. Dreams of alpine powder were quickly dashed at the sight of a wind-scoured south face. Unlike other mountains of it’s stature, Fossil only has viable descents on it’s eastern and southerly aspects, with the former only filling in late season, if ever at all. As such, we were confined to the talus studded and rime riddled south face staring us down, menacingly. However, fields of wind deposited snow on the lower angle run-out promised a reward for perseverance through the manky and icy upper. The south face of Fossil isn’t insanely steep, maxing out in the lower forty degree range, but still offers potential for a nasty tumble. Hellbent on summitting, armed with spiky implements and willing to retreat if necessary, we strapped on crampons, unsheathed ice axes and began kicking steps into the beyond.

Carl punching through wind buffed chalk on the lower face
Then it got firm…

The climb was routine, a classic mixed bag of shin deep powder, scree and bulletproof ice. In some sections we front pointed, in others we sauntered. The south face rises only a mere 700 feet from the saddle, 714 to be exact, meaning we topped out in a fraction of an hour. A nasty bitter wind kept us from much celebration. Two quick photos, peel the skins and adios!

I was prepared for a mixed bag of conditions, but Fossil took my expectations and doubled down. A half dozen chalky turns quickly became shark infested waters laced with dangerous patches of ice. Unable to hold an edge worth a damn, we cautiously side-slipped between rock islands, scoring sketchy turns wherever we could find a wind loaded pocket. Mid-mountain brought stable ribs of rippled powder, and beneath the westerly ridge we found mid-winter conditions, bottomless and care-free. Dining on a half frozen hummus sandwich and gazing back on our tracks, my heart filled with gratitude for such superb early season shredding. The best part? We were only getting started!


Ice Cave Couloir

The Sucker Hole beckons.

Any skier who has wandered through Darby’s North Fork has laid eyes on the Ice Cave Couloir. I believe the line got it’s name from a true Ice Cave concealed within or near by? Someone besides myself knows. North facing and guarded by massive limestone walls, this puppy never sees the light of day. Most of the season the “Ice Cave” is haunted by a ring of gargantuan cornices, and the upper walls see enough sun to release dangerous icy projectiles. No matter how tempting, travel in this couloir post-December is likely hazardous and potentially fatal – some call it the “sucker hole” – seems fitting. On our first Fossil mission years ago Carl and I fantasized about carving turns through the belly of this beast. With conditions aligned and stoke high as the sky, today seemed like the day to give er’ a rip.

Carl evaluating our snow-pit. A snowpack analysis will be included below this article!

After skinning through increasingly deeper and unconsolidated snow we decided to dig a snow-pit before entering the gun barrel. Our findings will be talked about in depth below, but a quick summary goes as follows: two distinct weak layers were present but failed to propagate on two separate ECT’s. The top was a shallow two inch wind skin that failed after about seven taps, and the suspect persistent layer, buried (very) approximately thirty inches deep, fractured after twenty taps (to reiterate, no propagation). Despite standing waist deep in a forty degree couloir, we were seemingly safe, and armed with avalanche confidence we loaded up for a journey into the Ice Cave Couloir.

Carl literally swimming up the Ice Cave Couloir

While the unconsolidated snow was our ally in avalanche safety, it was the arch nemesis of efficient climbing. Our average boot penetration was about three feet, and at points both Carl and I plunged to chest depths. After fifteen minutes of thrashing we had barely achieved fifty feet. Demoralized and considering retreat, I decided to put my skis on and attempt to skin up the now forty degree couloir. At first Carl thought I was crazy. At first I thought I was crazy. That said, skins worked! To the demise of our picturesque line I cut switchback after steep switchback up the narrowing slope, slowly but steadily gaining progress. In general, it is pretty bad form to skin up a couloir of this narrowness. Not only does skinning probably increase your likelihood of triggering an avalanche and getting caught in the slide, but it also decimates the snow conditions for you and any future parties. We rationalized our choice based on the remarkably safe snow and the relatively low chance of seconding skiers. As we zig-zagged several small sloughs broke on the two inch wind layer, but no signs of propagation or threat. If anything our skinning broke up the snowpack and eliminated any chance of wind slab avalanches. Eventually the couloir splits in a “Y” shape – I chose left. However, once the run deviates the slope degree cranks over fifty degrees, and try as I might I just couldn’t get enough purchase from my skins to continue. With each step I simply eroded the light density snow and slid downward. Obsessed and unwilling to concede, I took off my skis and began bootpacking again, finding a quasi-supportable surface after negotiating a small cliff band. Carl watched from below as I neurotically thrashed towards my ultimate demise, dead ending in a shoulder deep snow bluff a mere fifteen feet from the top – I suspect I was at the toes of buried cliff. I had finally reached my point of terminal exhaustion, and with Carl fifty feet below waving the red flag, I begrudgingly surrendered. The fact we made it this far was a miracle, and with at least thirty inches of Novemeber powder beckoning to be shredded, I was very very far from complaining.

Carl following my sinful skin track

As soon as I clicked into skis my aloof vision hyper-focused. My slope meter read just over fifty degrees, and this snow was deep! Carl had stopped before the angle kicked up, and bunkered beneath a rock as I hacked my first turns. Honestly, I’m not sure I’d ever skied fifty-plus degree snow in such deep conditions. Slough rained down steadily but was easily managed, and I returned to Carl with surprising ease. Despite being hardly above 10,000 feet, this couloir had a sort-of “epic” feel. Directly across the way stood Mount Bannon, The Grand Teton and Mount Moran’s striking Southwest Couloir. Terraced limestone walls towered hundreds of feet on either side, and our channel wasn’t much more than twenty feet wide. For a photographer, all the elements were there, and as Carl took first dibs in the belly I had a ball scoring some picturesque shots. I followed with only hoots and hollers for the second run in a row, taking a full pull through the couloir and blasting onto the apron with ever widening turns across a virgin snowscape. The run-out was just long enough for my mind to wander and develop conscious thoughts of gratitude – how blessed we are to live, learn and play in such a beautiful and wild place!

Carl shredding mid-winter conditions, in Novemeber!
(Moran and Table Mountain far left, Grand Teton dead center, Bannon front center-right and Fossil on far right)
We hacked it up – but had lots of fun!


Post couloir, many miles of lightly dusted meadow minefield skipping brought us to our foot trail. The upper Darby basin probably averages eight to ten degrees of steepness, allowing for a blissful egress with very little pole planting. The lower we cruised the thinner the snow became, until every bush older than six months was showing their newest haircut. After Carl put a Sharpie sized core shot in his Splitboard and I grinded to a tumbling halt amidst a field of pebble studded grass (no core damage, thanks Icelantic Skis) we folded our cards for the day. Three miles of mellow hiking saw us to the car around the eight hour mark beneath a golden fading sky. I’m consistently amazed at how early the sun sets this time of year.

State of the Teton Snowpack (11/21/2021)

On our Darby Canyon adventure, Carl and I sampled snow on all aspects above 10,000 feet. We also dug one snowpit on a pure north facing slope at ~10,000 feet. Below is a summary of our findings on each aspect, followed by an in-depth analysis of our snow pit. (Note: These findings are only directly relevant to our exact location. Conditions could vary accross the Teton Range and our findings should not be over-extrapolated to to other aspects, elevations or locations. See disclaimer below)

Easterly Aspects (10,000′)
Large areas of wind deposited snow. Light cornice formation. Relevant wind slab development. Lower elevations below 10,000 feet held one to two feet of powder.

Southerly Aspects (10,000-11,000′)
Alpine faces above 10,000′ are likely windswept. Observations on nearby peaks confirmed probable consistency across the range. Thin and firm snowpack, widespread ice and lots of exposed rocks. Mostly safe avalanche conditions.

Westerly Aspects (10,000′)
Time spent on westerly aspects was much less than others, but what little we observed was a mixed bag. Exposed slopes were wind hammered or swept clean. Protected slopes held healthy one to two feet of powder. No surface level avalanche signs were noticed, but preliminary signs seemed consistent with north facing aspects.

Northerly Aspects (9,500-10,200′)
As mentioned above, we dug a snow pit at approximately 10,000 feet and the findings will be discussed below. Surface level observations included sporadic wind loading and sloughing on steeper aspects. Several feet of consistently light density snow. Despite significant loading, snow-pack seemed resistant to propagation and no slab development was observed. Difficult boot-packing conditions due to unconsolidated snow. More information available below.

Snow-Pit Summary (North facing, 10,000′)
Our snow-pit was dug on a pure north facing aspect beneath a large and steep avalanche path at approximately 10,000 feet. We dug at least four feet in depth and preformed two extended column tests. Our findings are summarized as follows.

Two weak layers were present between the snow surface and the ground. The deepest (persistent) layer, most likely from the early season dump and subsequent dry spell in October, was buried by approximately 2.5 feet. The layer was softer than expected and took approximately twenty taps to fail. The failure produced a fracture without propagation. No slab development was observed.

The uppermost weak layer consisted of approximately one centimetre of groppel, upon which two to four inches of wind packed, medium density snow rested. This “wind slab” took seven taps to fail. The failure once again produced cracking without any propagation or signs of cohesive slab development. When ascending and descending the couloir, this layer presented itself in the form of small sloughs. In the steepest terrain (fifty plus degrees), small wind pockets the size of pizza boxes released on the groppel bed surface. This layer presented little to no danger to us, but could become very relevant with significant future loading, either from snow or wind events, and should be noted as a potential future hazard.

As of November 21st, 2021, The Teton Range snowpack seems mostly safe. The most relevant danger appeared to be isolated wind-slab development on easterly slopes above 10,000 feet. South faces appeared universally scoured but stable, and our experience on westerly slopes was not significant enough to provide any substantiated findings. North faces appeared cold, unconsolidated and mostly stable, with a weak persistent layer that seemed highly resistant to failure. The deep persistent layer is likely widespread and present on any slopes that did not completely melt clean after the October snowfall. Solar slopes that did not melt likely have a harder bed surface more willing to produce avalanches. The combination of easterly wind loading and a firm persistent weak layer is of particular concern. With extensive wind scouring, southerly aspects are now a prime suspect for future avalanches if coming storms hit heavy. Below 9,000 feet, the snowpack seems too thin to present much, if any, avalanche danger – but again, we didn’t dig any pits at this elevation.

Thanks for reading! As always, a mega shout-out to my sponsors, Icelantic Skis and Chasing Paradise, for providing me with wooden snow sliding sticks and wholesome fuel! If you used any of this information to inspire your own adventure, please consider subscribing or donating to Ten Thousand Too Far by clicking here. Also, I love love love comments! Not only is it cool to see my efforts don’t fall on deaf ears, but your adventures and appreciation get me stoked!

Skiing is dangerous. Mountains are dangerous. Any information in this article is strictly for story telling and informational purposes. If you chose to attempt anything you read about in this article, or use any of the information to plan your own adventure, you are doing so at your own risk.
Icelantic Ski Reviews: Shaman, Nomad, Pilgrim | The Ski Monster

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