scree

Imagine hiking up a steep mountain path. Above you, the rock face has been breaking apart for years. The small stones slide down and gather below, making a slope of loose rock. That is scree. It is common in mountains and can be hard to walk on because the stones move under your feet. The word usually refers to this natural layer of broken rock on a hillside or at the base of a cliff, not just any random pile of stones. A climber might cross a scree slope slowly, while a hiker may try to avoid it.

Scree refers to a collection of loose rocks and stone fragments that gather at the base of cliffs, steep slopes, or mountains. It forms when larger rock surfaces break apart through weathering, often because of freezing and thawing, and the pieces fall or slide downhill under gravity. Over time, this creates a slope covered with loose, broken stone.

The term does not usually mean just any pile of rocks. It is mainly used for rocky material that has naturally moved downslope and collected in one place. You will often see scree in alpine or mountainous regions where bare rock is exposed to strong weather. These areas can be small patches or wide slopes stretching across part of a hillside.

Navigating scree can be challenging, as the loose rocks shift and slide underfoot, making it difficult to maintain footing. Hikers and climbers often describe walking on scree as feeling like "walking uphill on ball bearings." When you hear the word, the usual image is a rugged mountain landscape with a slope of loose, shifting stones.