Geology

The Olympic Mountains, which form the heart of Olympic National Park, are relatively young in geological terms, having risen about 50 million years ago. The mountains, once sedimentary seabed, were thrust upwards by tectonic action -- namely, the movement of the Juan de Fuca Plate under the North American Plate -- and emerged above sea level as recently as 12 million years ago. The highest point in the mountain range, Mount Olympus, now stands at 7,829 feet, having lost some of its height to erosion and glacial action, which shaped the park's V-shaped valleys. A half-dozen glaciers, remnants of the last Ice Age, remain at the mountain's high altitudes.