Key takeaways
- Postholing is sinking deep into soft snow with each step, leaving leg-shaped holes.
- It happens when snow is too soft to support your weight, often as it warms through the day.
- It's exhausting and slow, and can be dangerous near hidden rocks, creeks, or tree wells.
- Avoid it with flotation (snowshoes or skis) and by traveling early when snow is frozen firm.
From the leg-shaped holes resembling holes dug for fence posts.
What postholing is
Postholing is the exhausting experience of sinking deep into soft snow with each step, punching your legs down and leaving behind a trail of deep, leg-shaped holes — like the holes dug for fence posts, hence the name. It turns travel into a slow, energy-sapping slog.
Why it happens
Postholing occurs when snow is too soft and unconsolidated to support your weight on top. It’s common in fresh snow and, classically, as the day warms and the sun softens a surface that was firm at dawn — so the same slope you cruised across in the morning can swallow you by afternoon.
A hiker crosses a snowfield easily on firm morning snow, summits, and returns in the afternoon to find the now-softened snow swallowing them to the thigh at every step — postholing the whole exhausting way back, wishing they’d brought snowshoes.
How to avoid it
Two fixes: flotation — snowshoes or skis spread your weight to keep you on top — and timing, traveling early when the snow is frozen firm. An alpine start that beats the afternoon softening is the classic defense. Watch out, too, for postholing near hidden hazards like creeks and tree wells.
The bottom line
Postholing — sinking thigh-deep into soft snow step after step — is one of the most exhausting and demoralizing forms of travel in the mountains, and occasionally a hazard near hidden obstacles. The fixes are simple: carry flotation (snowshoes or skis) and travel early on frozen snow. An alpine start that beats the afternoon softening can be the difference between gliding and floundering.
Frequently asked questions
What is postholing?
Postholing is sinking deeply into soft snow with each step, so your legs punch down and leave behind a series of deep, leg-shaped holes — like the holes dug for fence posts. It happens when the snow isn't firm enough to support your weight, making travel slow, exhausting, and frustrating.
Why does postholing happen?
It occurs when snow is soft and unconsolidated — too weak to bear your weight on top. This is common with fresh snow, and especially as the day warms and the sun softens a previously firm surface (often by afternoon). The deeper and softer the snow, the worse the postholing.
How do you avoid postholing?
Two main ways: use flotation — snowshoes or skis spread your weight so you stay on top of the snow — and time your travel for when the snow is frozen firm, typically early morning (an alpine start). On firm dawn snow you may walk easily on the surface, only to posthole on the same slope once the sun softens it hours later.
Sources
- Winter travel skills — The Mountaineers
- Snow travel — American Alpine Club