The normal route to the summit of Mount Rainier is the Disappointment Cleaver Route, YDS grade II-III. As climbers on this route have access to the permanently established Camp Muir, it sees the significant majority of climbing traffic on the mountain. This route is also the most common commercially guided route. The term cleaver is used in the context of a rock ridge that separates two glaciers. The reason for naming this cleaver a disappointment is unrecorded, but it is thought to be due to climbers reaching it only to recognize their inability to reach the summit. An alternative route to the Disappointment Cleaver is the Ingraham Glacier Direct Route, grade II, and is often used when the Disappointment Cleaver route cannot be climbed due to poor route conditions.