Big Sky off-piste & powder guide

Montana, USA · 2286m to 3418m · 2 documented zones

Finding powder at Big Sky

Big Sky hangs its reputation on Lone Peak, reached by a tram carrying fifteen people at a time. The Big Couloir off the top is among the steepest inbounds runs in North America, and it is one of very few pieces of lift-served terrain anywhere that patrol formally controls access to. The resort is candid that its alpine terrain carries real avalanche risk which control work reduces but cannot eliminate.

Lift-accessed zones — no walking

Ride up, drop in. These 2 zones need no hiking, which also means they are the first to get tracked out after a storm.

The Big Couloir

Lone Peak sector

Inbounds - patrolledExpert

One of the steepest inbounds runs in North America, and unusual in sustaining that steepness for the length of the descent. Inbounds, controlled, and still gated by patrol.

Inside the ski area boundary and actively avalanche controlled by patrol. Controlled does not mean safe: the resorts themselves are clear that control work reduces the risk without eliminating it.

Access rules

You must sign out with ski patrol, carry a transceiver and bring a partner. Patrol books parties into time slots and limits access to two skiers at a time. A shovel and probe are strongly recommended.

Lift access: Lone Peak Tram
Walk in: No hiking — Lift-accessed from the Lone Peak Tram, after signing out with patrol.
Getting back: Descends off Lone Peak back into the lift network.
Known hazards: Sustained extreme steepness
A fall would carry a long way
Real avalanche risk that control work reduces but cannot remove

Lone Peak upper terrain

Lone Peak sector

Inbounds - patrolledExpert

The wider spread of chutes and faces off the top of the tram, which is what makes the fifteen-person ride worth queueing for.

Inside the ski area boundary and actively avalanche controlled by patrol. Controlled does not mean safe: the resorts themselves are clear that control work reduces the risk without eliminating it.

Lift access: Lone Peak Tram
Walk in: No hiking — Lift-accessed from the Lone Peak Tram.
Getting back: Descends back into the Big Sky lift network.
Known hazards: Steep exposed alpine terrain
Avalanche risk despite control work

The avalanche danger scale

Every European bulletin uses this five-level scale. The column that matters most is the last one: around half of all avalanche deaths happen at level 3, not at the extremes, because that is when the snow still looks worth skiing.

1. Low

about 5% of fatalities

Generally stable snowpack. Triggering is only possible with high additional loads, and only in extreme terrain. Natural avalanches are small at most.

The most favourable conditions of the season. Terrain choice still matters in isolated extreme spots.

Forecast on about 20% of the season

2. Moderate

about 30% of fatalities

The snowpack is only moderately well bonded on some steep slopes. Triggering is mainly possible with high additional loads. Very large natural avalanches are unlikely.

Conditions look benign and catch people out. Roughly a third of fatalities happen at this level.

Forecast on about 50% of the season

3. Considerable

about 50% of fatalities

The snowpack is moderately to poorly bonded on many steep slopes. Triggering is possible even from a single skier. Large avalanches are possible.

The most dangerous level in practice. It carries about half of all avalanche deaths, because the skiing still looks good and the snowpack no longer needs much provocation.

Forecast on about 30% of the season

4. High

about 10% of fatalities

The snowpack is poorly bonded on most steep slopes. Triggering is likely even from a single skier, and numerous large natural avalanches are expected.

Off-piste travel should be limited to low-angle terrain well away from anything steep above you.

Forecast on only a few days a year

5. Very High

rare enough that no share is published

An extraordinarily unstable snowpack. Numerous very large and often extremely large natural avalanches are expected, even on moderately steep terrain.

Do not go off-piste. Roads and parts of the resort itself may be closed.

Forecast on very rarely forecast

Scale and statistics from European Avalanche Warning Services - Avalanche Danger Scale.

What you need to carry

Transceiver

Worn on your body, not in your pack, and switched to transmit before you leave the lift. Every member of the group needs one; a single person without makes the whole group less safe.

Probe

Pinpoints the burial once the transceiver has brought you close, so you dig in the right place first time rather than in a hole beside them.

Shovel

A real collapsible avalanche shovel. Digging is the slowest part of a rescue, and it is what actually gets your partner out.

Airbag pack (optional)

Helps keep you nearer the surface in a moving slide. It supplements the three items above and never replaces them.

How to ski it

Read the bulletin before you go, every day

The danger level, the problem type and the aspects and altitudes it applies to matter more than anything on this page. Conditions change overnight.

Practise with your kit until the search is instinctive

Owning a transceiver is not the same as being able to use one under pressure. Run search drills at the start of every season.

Never ski off-piste alone

Companion rescue is the only rescue fast enough to matter. Burial survival drops sharply after about fifteen minutes.

Ski steep slopes one at a time

Exposing one person at a time keeps the rest of the group free to dig, and reduces the load on the slope.

Hire a guide for terrain you do not know

Local guides know which aspects have loaded, which lines cliff out and where this season's weak layer sits. Every resort guide on this page says the same thing.

Plan the exit before you drop in

Several classic routes finish in a different valley or a long way from a lift. Know how you are getting home, and what time the last lift and last bus run.

Keep planning

Big Sky snow report & forecast Snow history & depth More resorts in USA