A cleaver is a mountain ridge that has been sculpted by glacial ice into uncommonly sharp proportions. The usage is largely limited to Washington’s Mount Rainier, which boasts seven named cleavers. The majority of the twelve thousand–plus climbers who attempt to ascend Rainier each year do so via Disappointment Cleaver, a dark blade of eroded lava that demarcates the Ingraham and Emmons Glaciers on the dormant volcano’s southeast ﬂank.

Jon Krakauer