Rating & Grading Ski Descents – D System in Real Life


This post by WildSnow.com blogger  

Editor’s note: The lead-up to winter is a good time to talk rating systems. Below has always been our rating system example and comment post (originally published in August of 2010), with link to the actual D System rating method page. This is a good time to re-up this post, and in the process remember Joel, who died in an avalanche in 2011. We’re not sure that rating systems will ever catch on in a big way, but they are useful on occasion, and common in European guide books. Worth pondering and discussing, in our view.

A few years ago the late backcountry snowboarder Joel Levenberg sent this question (edited version below) about the D System. It’s still a great way to focus discussion of the D System (and remember Joel), so here we go…

Taylor Glacier, Rocky Mountain National Park.
Taylor Glacier with complete glisse descent route marked. D System II D19 R3

“Lou, I’m curious about your opinion of what D rating would be assigned to Taylor Glacier in Rocky Mountain National Park. I snowboarded it many moons ago and did some slope measurements with a slope meter on the headwall that were beyond 60 degrees.”

“After the first two turns, the slope dropped down to mid to lower 50s and held that for about 400 vertical feet. There were cliffs to negotiate the entire way down. I’m including a pic a friend took recently after climbing it and a pic I took after my descent with my route painted on. Are you familiar with the route and if so what do you think? I’m proposing a II D19 R3. I’m just curious as to what your opinion is.”

Taylor Glacier
Top section of Taylor Glacier, showing 60 degree crux section.

Joel, thanks for an excellent example of the D System in real life. Taylor illustrates the importance of the D Scale crux rating as part of the D System, modified by considering the length of the crux and other factors. The length of the route is rated by the Roman numerals, and the “R” rating indicates the risk/danger. I’d say the grade II for length is close enough, and your R3 is reasonable as a danger rating. An R4 route would probably have items such as more objective hazards, longer steeps, or require skiing within inches of cliff edges.

If the crux is usually as steep as you measured it, that places it in the D 18 or above range. Since the crux is so short I’d be conservative in the rating (a shorter crux is easier than a longer one), but if the difficult part of the route is exacerbated by terrain features you have to work around or over, then that would bump it up. Thus, I’d think saying it’s a D19 would be fine, though it could be a D18 due to how short the crux is. Subsequent descents will gradually refine the rating, as in rock climbing ratings. Main thing and worth repeating over and over, remember that the D System is intended to rate difficuly of descents RELATIVE TO ONE ANOTHER. It’s not a math forumla, though it does use things like slope angle numbers to reach general conclusions about where a descent would rate in the total scheme of things. This is explained at length on our D System Page.

Joel, indeed, your example shows how the D Scale of the D System works in similar fashion to rating a rock climbing route using the YDS system (e.g., 5.11, 5.12, etc.), since you rated a route D 19 based on the crux.

More, this example illustrates how difficult it is for any rating system to completely reflect the nature of a route. In the case of the D System, a D19 route requires skill with terrain in the realm of 60 degrees steep. BUT, there is a big difference between a Grade II ski route and a Grade V. Likewise between an R3 ski route and an R4. While one might have the technical skill to ski or snowboard a D19 crux, can she handle that type of terrain if it’s sustained for hundreds or even thousands of feet, as in the case of Mount Robson? What if he’s been climbing for 12 hours before starting the descent? And what if the hazards of the route are causing extreme mental stress (otherwise known as fear?). Since the D System has a length and danger rating it addresses these concerns, but deciding whether to do a route or not will always require more than simply knowing a rating. As is the case with rock climbing. Thus, it’s important to include the length and danger rating along with the D Scale rating.

A while ago someone mentioned we should include the length of the crux in the D System rating. We felt that was getting too far over on the narrative side of things for a tight rating system. In other words, when does a rating become a guidebook description? Any rating system requires support from things like other people’s experience and guidebook descriptions. D System is intended to be tight and brief.

(Note, Taylor Glacier can be skied or snowboarded from lower down for a more moderate descent, and is frequently done that way. More, various starts are obvious in the photo and these could require different D Scale ratings if it’s common to pick between them.)

D System described here.

Comments

46 Responses to “Rating & Grading Ski Descents – D System in Real Life”

  1. BrianStory August 28th, 2006 9:30 am

    I skied the right arm (curves behind cliffs in upper photo) of Taylor Glacier in March 2006 from above the cornice and found it to be more like 55 deg. – steep but not outrageous. And the angle dropped off 10 50 deg. after a few turns. Winter snowpack must have produced mellower slope angles for me? I’d suggest III D15/16 R3. Other than the exciting cornice entrance, I didn’t find anything much steeper than “cruxes” on N. face on N. Maroon Peak (IV D15 R4). There are at least two other superb ski lines in this cirque.

  2. podenbeck August 28th, 2006 11:26 am

    What if the D system had (a-d) or plus minus ratings as well much like the YDS. This would solve the length of a difficult section. Say a 60 degree section only lasted 20 yds that might be a D19- and another line was 60 degrees for 1/2 mile D19+. This might tighten the system up. I think that the less numbers the better.

  3. Lou August 28th, 2006 12:12 pm

    Hi, yeah, that’s one way of looking at it, but really, that’s 6 of one half dozen of the other, and we felt the numbers were cleaner. The divisions are the same. D16 is D15+

    Remember that slope angle is only part of this. The rating is for how technically difficult it is to ski or snowboard. That includes how narrow the couloir is, how steep, how hard it is to do any required traverses, and more. Again, it’s like rock climbing. There is no one or two things that makes a route 5.11, ditto for D18.

  4. Rune Kvist August 29th, 2006 12:32 am

    Are you familiar with the adoption of a new rating system for ski-mountaineering in Europe – adopted from the american rockclimbing rating? (- i.e. divided into 5 classes each divided into three subclasse & the fifth grade ‘open’)

    It strikes me as a very similar in approach – check the link (in french):
    http://www.ffme.fr/ski-alpinisme/cotation/echelle-volo.htm

    It’s still in its early stages and there’s quite a bit of disagreement (esp. in france) on finetuning the rating concerning the fifth degree (notably between chx and ecrins/volopress group)

  5. Lou August 29th, 2006 5:31 am

    Brian, it appears we would indeed rate several different descent routes for Taylor Glacier, and that you and Joel did two different ones? If so, how about we call one the headwall to looker’s left and one looker’s right?

    The short cruxes definitely would cause the route to rate a bit lower on the D Scale.

    I’m also thinking that when we add the Taylor looker’s left headwall to the D System examples, it would be better to rate it II or III, D18 R3.

    Since the looker’s right has such a short crux, let’s go with D15 on that for now. The examples tell the story, remember that this is a linear rating scale and each route should fit in the scale in relation to the difficulty of other routes. Just like rock climbing rating. BUT, remember that the routes in the examples list are all subject to revision as to rating, I’d say many of them could go up or down a notch or two as we refine this. Ditto for the D Scale verbal descriptions, some of which might still have too much emphasis on slope angle.

    Rune, I’m familiar with the Volo system you’re speaking of, and we give a lengthy opinion of it at the end of the D System page.
    D System

  6. Rune Kvist August 29th, 2006 6:28 am

    Ups! Missed that ;-)

  7. Alan Angelopulos November 17th, 2008 8:19 am

    I recently viewed your ski descent ratings on this website. I noticed Mt Torreys has two descents rated: Dead Dog and the Tuning Fork. I’m wondering if the north face (you can see from I-70) has a rating.

    We skied it back in June of ‘93. We skied the line that looks like a giant funnel for the first 700 feet or so, then spills into another colouir on skier’s left.
    While skiing this line in 93 a guy from the summit followed us in- and ended up falling the first pitch and over the cliff at the bottom. Our epic descent turned into a rescue. He survived, and we were able to get him out by the afternoon. He fractured his hip and broke some bones in his face.

    Anyway, I skied the Tuning Fork this year, and while on the summit I looked down the north face and wondered, “how would Lou rate this?”

    Let me know if you have any thoughts on this,
    Thanks- Alan

  8. Lou November 17th, 2008 8:27 am

    Alan, I’ve not skied that route (only so many times I can make that road trip…). How about you try rating it? If someone could fall down it and get hurt or killed then then it’s R3 or R4, in terms of length grade III, but the difficulty? Somewhere around D 11 or above?

    The route you speak of is also called “Gunner’s” because it used to be fired on as a test slope by the avalanche howitzer crew, or so I’ve heard.

  9. Alan Angelopulos November 17th, 2008 10:35 am

    I would say D12 or D13 because it chokes down very narrow as it turns left into the other colouir. We had to straight line this section.
    Anybody else have a rating for this line?

  10. Rob A (in NJ) December 10th, 2008 9:58 pm

    hey guys,
    I like your system and I am wondering how it applies out here in the east.

    I’ve made two pages on summitpost.org of two ski routes that I did this past winter. I gave them a D-System rating in hopes of getting some feed back from others on how the D-System works out here. Here are the link to the two route I’ve posted. I was wondering what you guys think about the ratings I gave the routes.

    The Chute @ Tuckerman’s Ravine

    Bennies Brook Slide, Lower Wolf Jaw, Adirondacks, NY

    Thanks guys,

    Have a good winter.

    Rob

  11. Lou December 11th, 2008 7:15 am

    Rob, how about linking back to the D-System page somehow from the SummitPost route page? I’d appreciate that, and it would probably help users of the route description.

  12. Pat February 16th, 2009 9:46 pm

    Lou,
    To help fill out the D-System examples, Steve Romeo has been doing a three-part series on the Hossack-MacGowan Couloir.

    Might want to link ‘em.

    I think it’s a useful system. I always try to compare what I’ve done to what I want to do. Helps me figure out how close (or far!) I am.

  13. Stan Wagon June 24th, 2009 7:53 am

    I can’t agree with the D7 on Democrat N Face. I remember that Lou called this “extreme” in his 14er book. I skied it yesterday for the third time. The face is wide and there is some route latitude. But there is a nasty choke at the bottom of the usual exit (can be avoided by going far left, but few do that). And it is quite steep at the very top and though it eases, it is still pretty steep. The “feel” of all this to me is much more gripping than other routes around here in the D7-8 range. I say D9.

    Yesterday we did it, avoided the very bottom choke, which was not skiable, by traversing right so as to climb back to the Democrat-Cameron saddle, which makes the round trip much more compact than the other ways this is commonly done (5 hrs r.t.)

  14. Lou June 24th, 2009 8:11 am

    Hi Stan, thanks so much for the feedback. As with rock climbing, the D System works by consensus and opinion, so I’ll take a look at the rating.

    And, like rock climbing, D System does allow for some sand bagging (grin).

  15. Stan Wagon June 25th, 2009 10:06 am

    Re the Torreys post from last fall:

    Locals call that face on Torreys (the one on the N Face well east of the Tuning Forks) the Little Diamond.

    I have also heard “Emperor Face”.

    It gets skied quite a bit but I have not done it and so I cannot comment on the rating. But one accident was mentioned above and I recall another from a few years ago (different I think) where the fellow was very badly hurt and died after some months in a hospital . So this is clearly a line with some serious potential for mishap.

    My list including D-ratings of many Summit County and nearby routes is at the bottom of the page.

  16. Lou June 26th, 2009 1:56 pm

    Locals? I didn’t know anyone lived in Bakerville.

  17. Tony July 1st, 2009 8:06 pm

    Were the rating examples rated by the skiers who skied them or based on your estimates? Upon submitting this rating system, I suggest limiting the list

  18. Lou July 1st, 2009 8:21 pm

    Hi Tony, it’s some of both.

    What do you mean by “submitting this rating system” ?

  19. Mike February 23rd, 2010 10:46 am

    Lou,
    what would you rate the Y on Pikes Peak?

  20. Lou August 13th, 2010 10:28 am

    Mike, I’d rate that at D-11 or above. Total D System rating would be 2 D11 R3, meaning length grade 2, D grade 11 and risk grade 3

  21. Rob August 13th, 2010 3:00 pm

    A couple of other suggested ratings from 14er descents this spring:

    Little Bear Hourglass (IV D14 R4) Maybe Grade V. We did it with an overnight. Similar in steepness to Castle E face, though steeper at the top and in the choke, but no route-finding.

    Crestone Peak S Couloir (IV D11 R3) Again, maybe Grade V. We did an overnight. Similar to Cristo in steepness, except for very steep top section, thus the upgrade to D11.

    About right?

  22. Lou August 13th, 2010 3:42 pm

    Rob, thanks, I’ll add those in when I get a chance. When I do I’ll see where I think they should fit based on my experience as well, but I’ll bet you’re pretty close or spot on.

    Lou

  23. Caleb Wray August 13th, 2010 5:01 pm

    Can’t believe you haven’t rated the West Buttress yet Lou. (VII D7 R4), assuming the headwall ski is included. Without proper amounts of bacon it goes to a D8. What do you think?

  24. Lou August 13th, 2010 5:23 pm

    Yeah! I was under the impression that it was much less skiable than seems to be the case once the snowy season progresses. So it definitely needs a rating. It is definitely a D10. There is a tendency to under rate things. Don’t be shy, the D Scale has enough gradations and enough room to not have to shove everything to the lower end. The headwall does have a section that is easily 45 degrees and might exceed that at times, and some of those pitches on Washburn ridge were definitely cruxy. My opinion is it should be rated for approximately the condition we found it in. Any icier and it’s not a very legit ski descent as there would be way too much downclimbing. Any easier would be unusual. Danger rating should definitely be maxed, as should the length grade. I think the altitude and situation make the skiing harder, so bumping the D grade up a notch or two is totally legit within the D system. So it might be a D 11.

  25. daniel August 13th, 2010 5:53 pm

    it is one thing to ski a no fall 45 dg slope with good corn or powder, and entierly a differant thing to ski that same slope with hard snow or crust conditions.

  26. Mark W August 13th, 2010 10:11 pm

    Daniel makes a good point. A Boulder skier died when he fell on Taylor Glacier in hard summer snow conditions last year or the year before. In soft snow it would have likely been notably different to ski–hopefully with a different outcome for that skier.

  27. Bar Barrique August 13th, 2010 10:19 pm

    Hmmmm, this kind of quantifying backcountry descents goes against the grain. I agree that when taking people who are new to backcountry skiing out for a first trip, you have to make them aware of the risk management aspect; I think that the most important thing is to instill the fact that personal risk management is a priority. Rating systems in ski resorts do not necessarily work. There are so many variables to consider when deciding whether or not a backcountry route is safe. I’m sure that I am not alone, when I have felt like beating my head against a wall after taking some neophyte backcountry skiers on their first trip.

  28. Ptor August 14th, 2010 1:21 am

    A notch or two on the scale will always be relative to the person giving the rating. Conditions always play a role in apparent difficulty but I think that should not be included in the rating because everybody can wait and chose the conditions they like. Frozen tracks or removed snow from a previous party or partner can also add difficulty.
    In ze alps we deal with this number rating system that pretty much maxes out at 5.5 but this can seem simpler due to less gradations and the 5 clear divisions, (grade 1 to 4 max out at .3 with 5 going up to .5 so there are only 17 possibilities). I think it’s great to have a rating system to help relate and reference a descent to others and I can’t say which scale I prefer but regardless it’s a shame that there exists different rating systems that need to be converted between continents like in climbing.
    Sometimes people can get caught up in numbers, just doing ticklists with out a more profound inspiration. It’s amazing the amount of backcountry skiers here that are in shape and everything but don’t really ski well despite making their way down steep runs. They do the lemming thing when somebody blogs good conditions on a particular run to the point where they don’t even bother with the surrounding runs that are still virgin and ski the tracked out line. And that’s…OK

  29. Lou August 14th, 2010 7:08 am

    Bar, yeah, I’d agree that it’s problematic. It’s definitely an ongoing project and who knows if it’ll come to anything or not.

    Ptor, yeah, just because people use a grading system in different ways doesn’t make it wrong…

  30. Fernando Pereira August 14th, 2010 10:31 am

    I use the ratings, when they are available, as a check on the other information I got about a route I haven’t skied before by looking at the topo, photos, reading guidebooks and Web resources, and talking to people who have done it. I couple of times, the rating indicated that maybe I was being too optimistic in my assessment, and I chose what seemed to be easier routes. So, the rating serves as an overall check on my possibly inexact information gathering, which is a very good thing.

  31. Ome August 14th, 2010 3:14 pm

    If climbing has taught me anything, ratings are subjective and often born from the ego of the first ascentionist. Basically, why believe them? Ticking off routes based on numbers rather than aesthetics is for accountants. If it looks good, SKI IT!

  32. Bar Barrique August 14th, 2010 9:55 pm

    After thinking about this: I can agree that some kind of rating system can supply useful information. And; there is no easy fix for folks who are used to the “safe” thrills of an amusement park or video game from endangering themselves in the backcountry.

  33. Rune August 15th, 2010 11:14 am

    Pierre Tardivel and friends skied the Nant Blanc on the Verte i CHX back in June 2008 (and again in 2009). It was a slightly different route than Boivin/Siffredi – but he rated it 5.5 according to the toponeige system. See: http://www.skitour.fr/sorties/aiguille-verte,14023.html

    Could be interesting to see classics in the alps rated according to the D-system.

  34. Lou August 16th, 2010 7:20 am

    Everyone, we’re having some problems with comment spam attacks. As part of tuning my arsenal of anti-spam weapons I changed the comment “human verification” question. Just a reminder in case you’re in the habit of slamming the answer in there. Lou

  35. AP August 16th, 2010 10:51 pm

    HI Lou thanks for the great post!
    I think the current rating of D12 for Longs Peak North Face Cables Route is incorrect. The top section is 50 degrees + also skiing the crux slabs is gnar! Seems like most people these days rap the crux section. Also the rating for the Notch Couloir seems low D19? To my knowledge the Notch has never been skied without rope and has one mando rappel. A ski descent of the Notch that is off belay should rate higher than D19. Soon we will have a ski base jump rating…

  36. John January 25th, 2011 11:11 pm

    I read through this and am glad to finally see some kind of rating system for backcountry ski runs besides the system appropriated from resorts (greens, blue, blacks). But, I think that having 23 (or however many) levels is a bit ridiculous. The more levels you have within a rating system, the more subtle the difference is between them. Making it this difficult to tell the difference between each level seems counterproductive. There has to be a golden number, somewhere above three and below 25, that gives the reviewer ample room between levels so as to actually understand the difference between two slopes.

  37. Lou May 24th, 2011 7:48 am

    As many of you know, snowboarder Joel Levenberg died as the result of an avalanche on May 21 2011, on Torreys Peak here in Colorado. Joel made some good contributions to our D System project above, and while I’d never met him in person he seemed like a very sincere and well meaning individual, as well as a lover of mountains and glisse alpinism. My condolences to Joel’s family and friends. Lou

    Info here: http://tinyurl.com/3vz3lvb

  38. Bobby August 10th, 2012 7:26 am

    I’m growing to love the D system, particularly as the number of rated routes grows and as I’ve done more of them. There are many variables to be considered, but its a great tool for developing a relative sense of what a route could be like.

  39. Lou Dawson August 10th, 2012 2:20 pm

    John, about the number of ratings, if you read the explanation page you’ll see that in normal use of D System & D Scale the number of rating levels is far fewer. Only reason there’s a bunch is it has to start at 0 and be open ended, and be fine enough grained to be useful. Check out the details, I think you’ll see that it’s really not a big deal.

  40. Andy August 14th, 2012 6:33 pm

    Guess rating on the N. Face of Rogers Peak at Rogers Pass, accessed from the S side, skied to the glacier terminus with return via the col at the base of Sifton’s NE ridge… IV D16 R3? Sound legit?

  41. Lou Dawson August 14th, 2012 7:28 pm

    Andy, somewhat steeper crux than 45 degrees, with some terrain stuff, fairly long day? Sounds about right. Ultimately, you’d need to make sure you’d skied some other stuff that was rated, to get the perfect conclusion. Again, it can’t be emphasized that this is a relative rating system, just like the YDS rock climbing grades and many others.

  42. prophet66 August 15th, 2012 12:53 am

    What’s the point? Who is really going to care?
    Just to give some fixed rating to a constantly changing medium?
    I’ll be real pumped to listen to a couple dirtbags debate whether a descent is either a 5.10c or a 5.10d.
    This vanity to feel the need to classify such things will only serve to destroy the soul of backcountry skiing.
    Just let it be.
    Uncatogorized. How novel!

    Skier1 “What did you ski?”
    Skier2 “Nothwest Couloir of KY Jelly”
    Skier1 “What’s it rated?”
    Sier 2 “Who gives a ***!”

  43. Dan August 15th, 2012 9:43 am

    If you nneed a rating to help you make a decision as to ski or not to ski….why not climb it first? Then you can make your own decision. if you need someone to make that decision for you, maybe you should not be skiing/riding it?

  44. Lou Dawson August 15th, 2012 9:56 am

    Dan, in many cases I’d totally agree that’s true! In my view, rating systems are just another tool in the decision making toolbox. Route inspection is way more important. I think where people would be more likely to use a rating is for trip planning, say, when going to an entirely new place and figuring out some ski descents or tours. I know the rating systems in Europe are very popular for that.

    Another thing to remember is that the “climb it first” ethic has nearly ceased to exist. That’s resulted in some tragedies, but was somewhat inevitable due to things like increased helicopter and cable access, not to mention that some routes simply do not lend themselves to climbing (for example, a gigantic steep face covered with powder).

  45. Andy August 15th, 2012 11:17 am

    About the climb-it-first approach: our first day up at Rogers this winter in February, we told the park ranger we intended to boot up a couloir and then ski it. He looked at us as if we were nuts and said he’d never heard anyone suggest such a thing and questioned our competence. Coming from the PNW and maritime snow pack where booting up the line is standard, and sometimes the only option, I was kinda surprised at this. Given avy risk is frequently higher in a continental snowpack, do more people in those areas just base the go/no-go on a pit at the top and general observation, and figure the reduction in exposure is worth the risk of dropping in without full knowledge of the slope condition?

  46. Lou Dawson August 15th, 2012 11:59 am

    Andy, exactly. More, sometimes a rope is involved when evaluating stability at the top of the run, or cornice cutting, or both, etc… But those are all games it’s fun to play for a period in one’s life, though they’re not very sustainable…

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