TERRAIN CHOICE: THE VARIABLE YOU OWN

The Technique

1. Terrain is the only major variable you fully control, so it is where almost all of your safety comes from. You cannot change the snowpack, the weather or the fact that other people are on the mountain. You can change where you put your body. Every experienced rider who has been at this a long time has, without exception, converged on the same habit: on doubtful days they ride simple ground and enjoy it, and they save the big, complex, beautiful terrain for the days that support it. That habit is not caution for its own sake. It is the recognition that terrain choice is the one input that works reliably even when your read on the snowpack is wrong.
2. Learn the angles that matter. Avalanches most commonly release on slopes around 30 to 45 degrees. Below that range, slabs are far less likely to release under a rider, though the snow above you can still run onto you. Above that range, snow tends to sluff off continuously rather than build deep slabs, but the consequences of any slide are severe. Steepness is not something you can eyeball reliably; almost everyone underestimates angle by a meaningful amount, and a slope that "feels like thirty" is very often steeper. Carry an inclinometer, use it often on ground you are not committed to, and calibrate your eye over a season. Also measure the steepest part of the slope, not the bit you are standing on, because the start zone is usually above you and steeper than where you stopped.
3. Read aspect as a weather record. Aspect is the compass direction a slope faces, and it determines how the sun and wind have treated it. Sun exposed aspects build crusts, melt and refreeze, and warm quickly in spring, so they are where you expect wet problems in the afternoon and where you might find a supportive base in mid winter. Shaded aspects hold cold, dry snow for longer, which is why they hold the good riding, and they also preserve weak layers such as surface hoar and facets far longer. Lee aspects, meaning the ones the wind blows onto, collect wind slab. Because sun and wind vary with the season and the storm, aspect is not fixed advice, it is a question you answer using this week's weather.
4. Split the mountain into elevation bands and treat them as separate places. Forecasts do this for a reason: alpine, treeline and below treeline can have different problems, different danger ratings and different snow entirely. The alpine gets the wind and the loading and has no anchors. Treeline is where wind slabs and cornices are common and where the snowpack is often most variable. Below treeline is generally more sheltered, but it holds terrain traps and can still slide, and dense trees do not make a slope safe, they make being caught in it worse. When you plan, decide which bands you will enter and which you will not, and put that in writing.
5. Judge consequence separately from likelihood. A small slide in an open, smooth, gently tapering runout may not bury you. The same small slide above a gully, a creek bed, a stand of trees, a cliff band, a road cut or a terrain depression can bury you deeply or kill you on impact before burial. This is what terrain traps are: features that convert a modest avalanche into a fatal one, either by piling debris deep or by hurting you on the way through. Look below every slope you intend to ride and ask what happens to the snow, and to you, if it moves. If the answer includes a hole, a wall or a stand of timber, the acceptable likelihood drops sharply.
6. Learn to see the whole path: start zone, track and runout. The start zone is where the slab breaks, usually the steepest, most loaded part of the slope. The track is where it accelerates. The runout is where it stops, and it is often surprisingly far out onto flat ground, especially for large paths in a persistent problem cycle. People are killed standing on flat ground in a runout, at a lunch spot, in a car park, on a trail. When you pick a regroup point, look uphill and trace the possible path all the way to your boots. If you can see steep snow above you with an unbroken line down to where you stand, you are in the path, no matter how flat it feels.
7. Understand what forest, ridges and gullies actually do. Dense mature forest, thick enough that it is a nuisance to ride, is genuinely less likely to produce a large avalanche because the trees anchor the snow. Open glades and widely spaced trees are avalanche terrain, and they add trauma risk. Ridges and broad rolls are usually the safest lines through steep country because they are supported and shed snow to either side, though they carry cornices and cross loaded pockets on their flanks. Gullies are the opposite: they collect wind loaded snow from both sides, they concentrate any moving snow into a channel, and they are terrain traps by definition. As a working habit, travel on ridges and spurs, cross gullies quickly at their narrowest and lowest sensible point, and never travel up the middle of one.
8. Match the terrain to the day, in both directions. On a bad day, choose simple terrain: low angle, well supported, no overhead hazard, short slopes with clean runouts, sheltered from wind loading, with plenty of trees and options to retreat. Simple does not mean boring, and finding genuinely good low angle riding near you is a skill worth developing in advance, because a person with three known good low angle zones makes far better decisions on high danger days than a person with none. On a good day, with a settled snowpack and a problem you understand, more complex terrain becomes reasonable, and you should still travel it with full protocols. The mistake is to have only one plan and try to force it into whatever the day gives you.
9. Do the terrain work at home, where it is cheap. Before you leave, open a topographic map or mapping app and mark up the route: contour spacing to find the steep sections, aspect from the shape of the contours, slope angle shading if you have it, likely start zones above your line, the runouts you will stand in, the gullies and creek beds you will cross, and at least one bail out route from every part of the day. Treat slope angle shading as a rough guide rather than truth, because the underlying elevation data smooths out small steep rolls that are perfectly capable of burying you. The point of this work is that terrain does not change with the weather, so the map work you do once is good for every future trip into that valley.

Common Mistakes

Eyeballing slope angle instead of measuring it. Fix: carry an inclinometer, measure the steepest visible part of the slope, and check your guesses against it until your eye is calibrated.

• Regrouping at the bottom of the slope you just rode. Fix: pick regroup points out of the path, on a rise, a ridge, behind a rock band or well into dense timber, and look uphill from that point before you commit to it.
• Treating trees as automatic safety. Fix: judge the slope on angle, loading and what is below it, and count widely spaced trees as an added consequence rather than an anchor.
• Building a plan with one destination and no alternatives. Fix: leave home with a plan A, a simpler plan B and a plan C that involves no avalanche terrain at all, all mapped before you go.

The Drill

Map a run you already know without going there. Mark the start zones above your intended line, shade the sections between 30 and 45 degrees, mark every terrain trap, mark your regroup points out of the path, and mark two bail out routes. Standard: hand it to a partner who has ridden it and have them find the hazard you missed. If they find nothing, you have either done it well or you both share the same blind spot, so repeat the exercise with someone outside your usual group.

← Full survival & remote first aid curriculum