Much of the ski terrain that we desire falls within avalanche terrain. Whether skinning up a gentle ridge looking for first tracks into a couloir or finding progressively steeper terrain while skinning straight up a mountain, slope angles (and avalanche potential) increase with our natural desire to seek more challenging terrain. A thorough understanding of measuring slope angles can increase your safety margin and the number of ski days you enjoy.  Many skiers guess slope angles, and thus either overestimate, causing them to end up in unsafe terrain given the avalanche conditions or underestimate, causing them to lose out on a rewarding steeper slope.  Most of the time, we want to climb and ski as steep as possible when we leave the trailhead.  Accurate angle measurements have allowed me to ski as steep as conditions will allow over the past 30 years,  yet avoid chaos by just a degree or two.  In this article I endeavor to provide skiers with measurement tools and techniques that I have come to rely on every day when determining where to ski in the Chugach Mountains around Valdez.

        When entering avalanche terrain, the first question we ask ourselves is "Are avalanches occurring?"  To some, this seems like a simple way to make a "go or no-go" decision and they may just pack it in and go home if the mountains are alive.  But, in practical terms, we typically want to continue on our approach and keep poking around for good skiing.  The fact that avalanches are occurring is an important deterrent for avoiding avalanche terrain.  However, it can also cause one to prematurely turn around.  With the right tools and more inquiry about potential slopes, you can explore a bit more and possibly find outstanding skiing on appropriately angled terrain.
        For those wishing to pursue skiing even when avalanche conditions appear considerable or high, the next question a skier should ask themselves is "Is the slope steep enough to slide?"  Guessing in these situations is not an optional way to answer this question when faced with a decision that can result in serious injury or death.  Many times over the years I have chatted with visitors (and guides) about slope angles and am amazed at how far off even educated guesses can be.  I find that skiers tend to overestimate slope angles by 5 to 10 degrees.  It seems that the more experience a skier accumulates,  the less they feel they need to accurately measure slopes.  Complacency becomes a deadly trap to the veteran backcountry skier or accomplished guides as much or more than the newcomer beginning his pursuit of the backcountry ski experience.
         Two things seem to have dramatic effects on angle approximations.  The physical position of the viewer strongly influences the skier's perception.  For example, a photo taken of a skier head-on from a helicopter on practically any big Chugach slope significantly distorts the angle.  We have all seen movies that make slopes look incredibly steep using this cinematic effect, but when viewed from a different orientation (such as at a right-angle across the fall-line), the slope appears much less steep.  All slopes seem steeper when standing at a distance looking at them directly compared to viewing them from the side, base, or top.   Thus, one piece of advice I offer is that even when approaching a slope on skins, skiers can assume the slope will measure less at the base than from a guesstimate a mile away on the valley floor.
         Ego, or the human factor, can also distort angle estimates.  I see this most often in situations where a skier is bent on impressing friends with a tale of an extreme line.  I hear fellow skiers chat about skiing at 45 degrees or higher, when in reality, in the Chugach, these high-angle slopes are laced with rock and cliffs and rarely hold snow because they are constantly sluffing and the remaining snow is entrained in terrain features.  Though we all want to say we skied "45 degrees", most of us are really skiing 32-40 degree slopes.  Unlike the steeper slopes, slabs form best at these moderate angles which are are the deadliest to skiers around the world.  On these slopes,  guessing is not applicable to skinners and ski mountaineers wanting to live another day.  I believe skiers should not feel lessened by knowingly skiing these lower angles.  As a matter of fact, it take as much practice and applied route-finding skills to travel safely at these moderate angles as it takes ski skills to descend the steeper lines with low avalanche potential.  At higher angles, the primary threat is falling, not avalanches.

         The angle of repose for granular (not slab) snow is 28 degrees.  32-40 degrees are the most deadly angles for slab conditions.  An accurately measured slope angle is a unique field observation because it gives us the only objective number in the avalanche game. All other information we collect is subjective with the possible exceptions of elevation and aspect.   Fortunately avalanche experts and savvy backcountry skiers for years have been measuring slope angles accurately using a variety of instruments.
        As a community of skiers, we know a lot about avalanches but not enough to offset the human error inherent in stability tests such as Rutschblocks and isolated column test.  This is apparent in that we have assigned the color Yellow, falling somewhere between Green and Red, to represent an ambiguous value.  Even in forecast text we temper hazard ratings with words like "possible", "probable", "likely" and "unlikely".  We just don't understand snow stability enough to be absolutely certain.  But, in this world of imprecision, we can be sure about one thing--the slope angle.  Even better than one angle is an accumulation of angle measurements.  This collection can allow you to map your favorite ski runs, giving you an objective margin of safety when avalanche danger is high.

        Engineers developing avalanche mitigation projects near population centers and highways use a variety of high-tech devices to determine slope angles.  As backcountry skiers we have different needs.  We need a tool that is accurate, but also handy, lightweight, and durable.  Over the years I've experimented with all sorts of instruments.  The expensive Suunto allows you to sight through a small monocular-like device.   While the Suunto is very accurate, it can only be used in one application, to sight directly up or down a slope.  The Suunto Clinometers (4 to choose from) are useful to the soloist when compared to Method 3 listed below because you don't need a partner.  Some devices employ a printed card with a compass rose with an archaic tangle of weighted strings.  The Backcountry Field Card with a plumb bob weight system and similar devices are worthless in winds or attempting observations in cold weather with mittens or gloves and are subject to constant error thus are not recommended.  I have also tried a navigation compass.  While lightweight, the compass's limitations include requiring muliple adjustments in the field and being difficult to read in inclement weather. Numerous other skiers have developed personalized angle measuring implements, all of which I'm sure have their own sets of advantages and disadvantages.
 
 
 

BACKCOUNTRY FEILD CARD - Plumb Bob Type $8.00

SUUNTO CLINOMETER 4TYPES $170

        Out of all these options one instrument has emerged to meet the daily demands I place upon it, the Life-Link Slope Meter.  It provides accuracy, flexibility, simplicity, and multiple options of measurement.  In addition, at just under $20, the Slope Meter is a great deal compared to the expensive Suunto ($150-$200).
         I recommend "bomb-proofing" the Slope Meter prior to use, having broken a few before applying a simple fix to give it more durability.  The most common break point is a crack in the plastic bubble  Though it breaks easiest in cold weather, even with normal use, it will eventually crack, leaving you scrambling for a replacement.  To rectify this issue, tape three 1/4" strips of cardboard to the back of the card and then "laminate" them in place with duct tape.  I also add one strip over the bubble guage (See Pic 1 and 2). This pads the card. The card I am currently using has lasted three seasons, measured hundreds of slope angles, and has no doubt been smashed and banged persistently in my pocket.  Crude but practical!
        Below are three methods I have found useful and easy to perform with this device.  These methods are only practical if the Slope Meter is kept constantly handy, such as in an outer pocket.  The easier it is to retrieve, the more you will reach for it when you realize that guessing slope angles is a step towards a bad decision.

PIC 1 $17.00

PIC 2

        The most important advantage of the Slope Meter is that it allows you three simple and quick methods for determining a slope angle and solving a variety of route problems.  These methods take only minutes away from your ski day.
        The most common method (Method One) is to simply lay a ski pole on the snow parallel to the fall-line.  Next, place the Slope Meter on the pole and take a reading.  This method works well on small terrain features and for finding the correct angled sample slope on which to dig a hasty or full profile pit.
         A second method (Method Two)  is especially handy when traversing slopes that grow progressively steeper.  By holding your card at arm's length in front of you and sighting the card edge on the  snow/horizon line directly in front of you and at the same elevation, one can determine the slope angle before getting to it.  It does not work to measure slopes even slightly above or below you due to angular distortions, so you may have to reposition yourself to get the proper perspective.  This can also be used to measure distant slopes as long as you have a clear view of the slope and skyline and the slope is at the same elevation as your position.
 

Method One

Method Two

        Method 3 requires a partner and works for determining large slope and alpha angles.  To maximize accuracy, it uses a longer sighting line than simply the card by itself.  A ski pole is about 4 feet long and makes an excellent sighting line.  First kneel as close to the snow as possible and sight along the pole shaft to a point above (or below) your position on the snowpack.  Hold the pole steady and place the Slope Meter on the pole.  Have your partner  stand to the side and note the angle.  Using this method, I have made a side-by-side comparison with a Suunto and have gotten the same accurate reading from my Life Link.
 

Method 3 0photo by P. Nylund)

Method 3

         I cannot overemphasize the importance of measuring slope angles and the degree to which it can improve your safety and access in the backcountry.  Measuring slopes reinforces your commitment to understanding avalanche potential and increasing your mountain awareness.   Bad decisions in the mountains often stem from ignoring basic clues of instability and failing to adhere to simple and proven protocols when evaluating avalanche potential.  Accurately measuring slopes will give you an added margin of safety that can make the difference between a great ski day and chaos.

ANSWER:  32 Degrees.  North Face Little Odessey.