What actually is scree?

Scree is those slopes of loose, angular rock fragments you find below cliffs and crags. They form when weathering breaks bits off the rock face above and gravity pulls them down into a pile that shifts annoyingly underfoot when you walk on it.

Why is scree so hard to walk up?

You're fighting both gravity and instability at the same time. Scree naturally sits at the steepest angle it can without sliding (around mid-30 degrees), so every step you take disturbs the loose fragments and they slide back down—hence the classic two steps up, one slide back experience.

Why are scree fragments sharp and angular instead of smooth?

Because they haven't travelled far enough to wear their edges down. Scree has literally just fallen off the cliff above and tumbled a short distance, so it's still sharp-edged and fresh-looking—unlike river pebbles that get rounded from being rolled and tumbled over long distances.

How the Hills Got Here

Why Scree Collects Below Crags

Water freezes in cracks beneath exposed crags, expands and loosens blocks of rock. Repeated freeze-thaw cycles send the fragments downhill, where gravity gathers them into the scree slopes walkers cross.

27 August 20266 min read