READING A FACE: LINE SELECTION FROM THE AIR

The Technique

1. Start with the whole mountain, not the line. On the flight in, your first job is aspect and altitude, and you should have both fixed before you look at any single feature. Work out where north is from the sun and the shadow line, then name the aspect of the face out loud in your head: north east, wind loaded, holding cold snow. That single sentence carries most of the snowpack information you need. North and east aspects in the southern hemisphere hold soft snow longer but also hold buried weak layers longer. Sun affected aspects settle and stabilise faster but turn to crust and then to slop with a predictable daily rhythm. Altitude matters as much as aspect: the same face can be blower at the top, dense in the middle and glue at the bottom, and the transition between those bands is where people get surprised. If you cannot name the aspect and rough elevation band of every part of the run, you are not reading the face yet, you are just admiring it.
2. Then read the wind, because the wind wrote the snow surface and it wrote it recently. From the air the tells are obvious once you know them: scoured, textured, matte grey snow on the windward side; smooth, rounded, slightly bulging snow on the lee; cornices curling over ridgelines and pointing where the wind came from; sastrugi ridges running across open flats like sand ripples. Pillows that look plump and pale and slightly overhanging are wind loaded, and wind loaded means both the best turns and the most reactive slab on the face. Look for the transition line where scoured meets loaded, because that is where the slab thins and that is where a rider most often triggers it. Cross-loading is the one people miss: wind running along a face rather than over it loads the lee side of every small gully and rib, so a face can be scoured overall and still carry a dozen small loaded pockets inside it.
3. Now find the terrain traps before you find the line. Terrain traps are the features that convert a small slide into a serious burial: gullies, creek beds, moats, flat run-outs, benches that catch and pile debris, cliff bands that a moving mass will carry you over, and trees that a moving mass will carry you into. The question is never only "will this slide" - it is "if a small amount of snow moves while I am on it, where does it take me and how deep does it pile". A metre of moving snow on an open apron that runs out onto a broad glacier is an inconvenience. The same metre in a tight gully with a bend at the bottom is a burial. Mark the traps on your mental map first, in red, and then draw your line so it never crosses one at speed and never stops above one.
4. Pick the safe zones next, and pick them before you pick the turns. A safe zone is a place you can stand where nothing above can reach you and nothing below can pull you in: the uphill side of a substantial rock rib, a ridge crest, a bench on the outside of the fall line, a stand of mature timber with real trunks rather than saplings. Plan the line as a chain of safe zones with skiing in between, and name them in order before you drop. This is the discipline that separates guided professional descent from just going. It also gives you a structure to fall back on if the face does something you did not expect, because you always know where the next island of safety is and roughly how many turns away it sits.
5. Now trace the line itself, and trace it in reverse. Start at the run-out and work up, because the exit is the part that gets forgotten and the part that traps people. Where does the face actually end? Is there a bergschrund, a moat, a cliff band below the apron, a creek gully, a flat where you will have to skate a long way? Then work upward through the mandatory sections - the places where terrain forces one specific choice - and connect those with the optional sections where you have room to improvise. Every big line reduces to two or three mandatory moves and a lot of freedom between them. If you can name the mandatory moves, you can ski the line. If you only remember it as a shape, you cannot.
6. Read where your own snow will go. On anything steep enough to be interesting, snow will move with you, and the fall line for loose snow is not always your fall line. Sluff runs the terrain: it follows gullies, it accelerates on convex rolls, it pools on benches, it shoots off spines and gathers in the troughs between them. From the air, look for the natural drainage of the face and note where sluff will concentrate. Then plan an escape side for each steep section - a rib, a spine, a bench edge you can move onto when the snow you released catches up. Riders who look strong on steep faces are usually just riders who decided where their snow was going before they left the top.
7. Memorise it with handrails, not with pictures. A photographic memory of a face fails the moment you are standing on top of it, because from above everything is foreshortened and the features you memorised in profile are now invisible. What survives is a sequence tied to features you can see from the top: "drop in skier's left of the rock horn, four turns to the flat-topped boulder, cut hard right onto the rib before the roll, follow the rib to the bench, exit skier's right of the ice fall". Handrails are the persistent objects - rock horns, distinct trees, colour changes in the rock band, a shadow line, the exact shape of a cornice. Say the sequence aloud in the machine. Say it again on the ridge. The one you can recite is the one you can ski.
8. Then make the honest call about whether you ski it at all. Line selection is not the same as line acceptance. Once the line exists in your head, hold it against four things: the day's avalanche problem and whether your line has any terrain that matches it; your consequence tolerance if the worst credible outcome happens on the worst section; your group's actual ability on the hardest single move, not their average; and the light, because a face you cannot see the texture of is a face you are skiing blind. The professional answer to "should we ski it" is usually "not today, and here is the thing that would have to change". Getting comfortable saying that in front of people you want to impress is the hardest technical skill in this entire lesson, and it is the one that keeps you working.

Common Mistakes

Reading the line and skipping the exit. Fix: trace every face from the run-out upward, and never commit until you can name what the line ends in.

• Memorising a photograph instead of a sequence. Fix: build the line as an ordered list of visible handrails with a directional call attached to each, and recite it out loud twice before you drop.
• Treating a scoured face as uniformly safe. Fix: hunt for cross-loaded pockets on the lee side of every rib and gully within the face, because those are the small slabs that catch strong skiers.
• Choosing the line before finding the terrain traps. Fix: mark traps first, then draw a line that never crosses one with speed and never rests above one.

The Drill

On any lift-served day with a view of a large face, give yourself sixty seconds of looking, then turn your back and write out the line in full: aspect, elevation bands, three terrain traps, three safe zones in order, two mandatory moves, the sluff escape side, and the exit. Turn around and check. Repeat until your written map matches what you see at least four times out of five, then reduce the looking window to thirty seconds. That thirty second window is roughly what a real pass in a helicopter gives you.

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