– The Backcountry Ski Site
  • Avalanches
  • Gear Reviews
    • Ski Reviews
    • Boot Reviews
    • Binding Reviews
    • Snowboard Splitboard
    • Book Reviews
    • Avalanche Beacon Reviews
    • Airbag Backpacks
    • Backcountry Electronics
    • Misc Gear Reviews
  • Podcast
  • Tips & Tricks
    • Ski Touring Basics
    • Boot Fitting
    • Fitness & Health
    • Gear Mods
  • Trip Reports
    • Fourteeners
    • Huts – Cabins – Lodges
    • Denali McKinley
    • 8,000 Meter Skiing
  • Stories
    • History
    • Humor
    • Land Use Issues
    • Evergreen Ski Touring
    • Poetry
  • Resources
    • All Posts Listed
    • 100 Recent Comments
    • Backcountry Skiing & Ski Touring Webcams
    • Ski Weights Comparison
    • Archives of WildSnow.com
    • Authors Page
    • Ski Touring Bindings
      • Trab TR2 Index and FAQ
      • Salomon Guardian & Tracker
      • Naxo Backcountry Skiing Bindings – Info Index
      • Silvretta Pure Backcountry Skiing Bindings – Info Index
      • Marker F10-12 Duke Baron
      • G3 Onyx Ski Binding FAQ
      • G3 ION Ski Touring Binding
      • Fritschi Backcountry Skiing Bindings – Info Index
      • Fritschi Diamir Frame Bindings Mount DIY
      • Fritschi Diamir Bindings FAQ
      • Fritschi Tecton FAQ
      • Atomic Salomon Backland MTN
      • Dynafit Tri-Step Binding 2001-2003
      • Naxo randonnee alpine touring AT ski binding FAQ
      • Dynafit Skiing Bindings – Info Index
      • Dynafit Binding Frequently Asked Questions FAQ
      • Dynafit Beast 16 FAQ Review 1
      • Dynafit Beast 16 FAQ Page Two
    • History
      • Ski Touring Binding Museum
      • Trooper Traverse Intro & Index
      • Randonnee Ski Touring “AT” ski gear — What is Hip?
      • Chronology
    • Backcountry Skiing Core Glossary
    • Gear Review Policy & Disclosures

– The Backcountry Ski Site

  • Avalanches
  • Gear Reviews
    • Ski Reviews
    • Boot Reviews
    • Binding Reviews
    • Snowboard Splitboard
    • Book Reviews
    • Avalanche Beacon Reviews
    • Airbag Backpacks
    • Backcountry Electronics
    • Misc Gear Reviews
  • Podcast
  • Tips & Tricks
    • Ski Touring Basics
    • Boot Fitting
    • Fitness & Health
    • Gear Mods
  • Trip Reports
    • Fourteeners
    • Huts – Cabins – Lodges
    • Denali McKinley
    • 8,000 Meter Skiing
  • Stories
    • History
    • Humor
    • Land Use Issues
    • Evergreen Ski Touring
    • Poetry
  • Resources
    • All Posts Listed
    • 100 Recent Comments
    • Backcountry Skiing & Ski Touring Webcams
    • Ski Weights Comparison
    • Archives of WildSnow.com
    • Authors Page
    • Ski Touring Bindings
      • Trab TR2 Index and FAQ
      • Salomon Guardian & Tracker
      • Naxo Backcountry Skiing Bindings – Info Index
      • Silvretta Pure Backcountry Skiing Bindings – Info Index
      • Marker F10-12 Duke Baron
      • G3 Onyx Ski Binding FAQ
      • G3 ION Ski Touring Binding
      • Fritschi Backcountry Skiing Bindings – Info Index
      • Fritschi Diamir Frame Bindings Mount DIY
      • Fritschi Diamir Bindings FAQ
      • Fritschi Tecton FAQ
      • Atomic Salomon Backland MTN
      • Dynafit Tri-Step Binding 2001-2003
      • Naxo randonnee alpine touring AT ski binding FAQ
      • Dynafit Skiing Bindings – Info Index
      • Dynafit Binding Frequently Asked Questions FAQ
      • Dynafit Beast 16 FAQ Review 1
      • Dynafit Beast 16 FAQ Page Two
    • History
      • Ski Touring Binding Museum
      • Trooper Traverse Intro & Index
      • Randonnee Ski Touring “AT” ski gear — What is Hip?
      • Chronology
    • Backcountry Skiing Core Glossary
    • Gear Review Policy & Disclosures
   

Rating Backcountry Ski and Snowboard Descents With S System

by Lou Dawson September 21, 1995
written by Lou Dawson September 21, 1995

Recommended: D System Ski Descent Rating Method

A simple system of “easy, moderate, hard, extreme” works well for rating a ski or splitboard climb. Rating the downhill is tougher. Many guidebooks over-simplify, while a few take the risk of using a true rating system. One method is the European S System (also known as the Traynard System). It’s based mostly on slope angle, and just as rock ratings assume dry conditions, so the S system assumes reasonable snow.

The type of environment where avalanche safety techniques are essential for skiers.

Skiing Independence Pass, Colorado. This route would rate about S4-.

The S system was first proposed for North American use in the 1980s by guide Bela Vadaz, it was expanded by guidebook author Louis Dawson in 1998 to include a +/- split for each level, and first published in the Chuting Gallery Wasatch guidebook by Andrew McLean. The problem with the system now is that it needs more levels around the 45 degree angle, so thus may need a shift lumping the easier/flatter terrain in a broader category. Here at WildSnow.com we do NOT recomend using S System for rating ski descents, it is too limited. Check out our D System, it’s better (see link above).


Again, please note that this Modified S System is NOT RECOMMENDED and is detailed here for the historical record. For a fresh new and effective rating system, see the D System.

Difficult surfaces, such as ice or breakable crust, will make the route harder than the indicated rating. As with rock climbing rating, it’s assumed that the snow is in reasonable condition, ice or difficult snow would change the rating. All ratings assume the competent use of your chosen glisse method: telemark or latched heel skis, or snowboard.

  • S0,
    Flat ground or slightly rolling terrain. Usually a flat
    ski tour or nordic trail. All hills can be easily descended
    on foot or with novice downhill technique.
  • S1,
    Easy. Low-angled.. Only novice downhill technique required.
  • S1+,
    Slightly harder than S1.
  • S2-,
    Angle up to 25 degrees. Easy terrain such as broad slopes.
    Ability to sideslip and stem-turn will get you down. Avalanches
    unlikely or impossible.
  • S2,
    Longer pitches than S2-, can be a steep narrow trail or
    actual glisse descent. Up to 25 degrees. Novice skiers
    or snowboarders can handle this terrain with basic technique.
  • S2+,
    Angle near or at 25 degrees, but rougher terrain or difficult
    snow requires more technique.

  • S3-,
    Slopes up to 30 degrees, similar to an easy "expert" run
    at a resort. Avalanches uncommon but possible with unstable
    snow.

  • S3,
    Slopes around 35 degrees, similar to an "expert" run
    at a resort. A skier or rider capable of S3 should have
    solid technique in any type of snow. This is often prime
    avalanche terrain. Example: Tuning Fork on Torrey’s Peak,
    Colorado, via easiest entrance at looker’s right.

  • S3+,
    Same angle as S3 (around 35 degrees); but terrain features
    (dogleg turns, rollovers, trees, ridges, etc.) make the
    skiing slightly more difficult. Again, this is prime avalanche
    terrain.
  • S4-,
    Slopes over 35 degrees but under 45 degrees, without terrain
    obstacles and with safe runouts. Avalanche danger is always
    a concern.
  • S4,
    Slopes over 35 degrees but under 45 degrees, usually steeper
    than an S4-, may have fall potential and terrain obstacles
    such as narrows. Avalanche danger always a concern.
  • S4+,
    Slopes just under 45 degrees, may have fall potential and
    terrain obstacles. S4+ is borderline extreme skiing and
    snowboarding. Avalanches are slightly less common on these
    slopes, but nonetheless occur enough to be a concern.
  • S5-,
    Slopes at 45 degrees or slightly over. Fall potential on
    firm snow. This is bonafide extreme skiing. Because snow
    can’t easily accumulate at these angles, slab avalanches
    are less common, but can occur. Loose snow avalanches are
    common.
  • S5,
    Slopes between 45 degrees and 55 degrees. Technique for
    steep terrain required if turns are made. Fall potential
    almost always present. Loose snow avalanches are common,
    especially after new snow accumulations; slab avalanches
    are uncommon.
  • S5+,
    Most of the route near or at 55 degrees. This is technical
    extreme terrain. Fall potential always exists. Death from
    a fall likely if steep sections are long. Loose snow avalanches
    are common, especially after new snow accumulations; slab
    avalanches are uncommon.
  • S6-,
    Short sections steeper than 55 degrees. Loose snow avalanches
    are common, especially after new snow accumulations; slab
    avalanches are uncommon.
  • S6,
    Most of the route steeper than 55 degrees. This is extreme
    terrain that’s safe for only the elite athlete if turns
    are made. Sideslipping and ropework may be mandatory. Loose
    snow avalanches are common, especially after new snow accumulations;
    slab avalanches are uncommon.
  • S6+,
    Same angles as S6, but with extenuating circumstances,
    such as cliffs, icefalls, and other obstacles. Avalanches
    are the least of your concerns. You might be better off
    on crampons so you can claim a first ascent.
  • S7-,
    A number of sections approaching 60 degrees steep; short
    sections may be 60 degrees. Fall potential a given. Avalanches?
    Who cares.
  • S7,
    Much of the route is around 60 degrees steep. Ropework
    may be optional or mandatory and should be clarified in
    rating and text description. Any avalanches probably happened
    before you got there.
  • S7+,
    Same angles as S7, with skiable snow connected by technical
    maneuvers such as small jumps. Ropework may be optional
    or mandatory and should be clarified in rating.
  • S8 The future
  • Lou Dawson

    WildSnow.com publisher emeritus and founder Lou (Louis Dawson) has a 50+ years career in climbing, backcountry skiing and ski mountaineering. He was the first person in history to ski down all 54 Colorado 14,000-foot peaks, has authored numerous books about about backcountry skiing, and has skied from the summit of Denali in Alaska, North America’s highest mountain.

    www.loudawson.com
    0
    Email
    previous post
    Romancing the Snow
    next post
    Battle of the Bulge — Mountaineering past mid-life

    Trip Reports

    • A Small Hut for Big Skiing in the San Juans: Aladdin’s Lamp

      April 23, 2024
    • Revisiting a 2011 Trip Report: Adventure in the Pickets — Thread of Ice Ski Descent

      December 9, 2022

    Avalanche Department

    • Ask a Forecaster: Q&A with CAIC’s Andrew McWilliams

      March 10, 2024

    Tips & Tricks

    • Transition Efficiencies 101 with Tech Binding Heel Units

      January 6, 2023
    • Visualizing the Backcountry as a Splitboarder: Minimizing the Challenges of Movement by Anticipating Terrain

      December 5, 2022
    • TURBOCHARGE YOUR TRAILHEAD BEACON CHECK

      November 15, 2022

    Recent Comments

    • Daniel on Backcountry Ski Boots Buyer’s Guide: The Touring Boots Worth the Money
    • Jim Milstein on Best Touring Packs for Guides and Daytrippers
    • Bergen Tjossem on Much more than a steep ski: Fischer Transalp 92 CTI Long-Term Review
    • Maciej on Much more than a steep ski: Fischer Transalp 92 CTI Long-Term Review


    • Facebook
    • Twitter
    • Instagram
    • About Lou Dawson
    • Terms of Service
    • Authors Page
    • About
    • Contact
    • Advertise
    • Copyright & Legal
    • Website Security

    @2025 - All Rights Reserved. Designed and Developed by WildSnow


    Back To Top

    Read alsox

    Polar Star Inn Hut Report: Mellow...

    March 7, 2025

    Best Touring Packs for Guides and...

    March 3, 2025

    Moment Wildcat 108 Tour Long-Term Ski...

    February 10, 2025