Snow cornice Snow cornice A snow cornice or simply cornice (from the Italian cornice meaning "ledge") is an overhanging edge of snow on a ridge or the crest of a mountain and along the sides of gullies. They form by wind blowing snow over sharp terrain breaks (e.g. the crest of the mountain) where it attaches and builds out horizontally. This build-up is most common on the steeper and leeward sides of mountains. Cornices are extremely dangerous and travelling above or below them should be avoided. When a cornice "collapses", it breaks in from the cornice to the top of the peak;
Ahtanum Ridge Ahtanum Ridge Ahtanum Ridge is a long anticline mountain ridge in Yakima County in the U.S. state of Washington. It is located just south of the city of Yakima, and much of its length is at the northern edge of the Yakama Indian Reservation. Ahtanum Ridge is part of the Yakima Fold Belt of east-tending long ridges formed by the folding of Miocene Columbia River basalt flows. Ahtanum Ridge separates Yakima Valley on the south from Ahtanum Valley on the north. At the eastern end of Ahtanum Ridge the Yakima River flows through Union Gap. The ridge continues east of