Established: June 29, 1938
Size: 922,000 acres
Encompassing 1,441 square miles of the Olympic Peninsula, Olympic National Park invites visitors to explore three distinct ecosystems: subalpine forest and wildflower meadow; temperate forest; and the rugged Pacific shore. Because of the park's relatively unspoiled condition and outstanding scenery, the United Nations has declared Olympic both an international biosphere reserve and a World Heritage site.
Inside the park, the Olympic mountain range is nearly circular, contoured by 13 rivers that radiate out like the spokes of a wheel. No road traverses the park, but a dozen spur roads lead into it from US 101, making it easily accessible from outside the park.
Residents of the Olympic Peninsula refer to it as a gift from the sea, and its features were indeed shaped by water and ice. The rock of the Olympics developed under the ocean—marine fossils are embedded in the mountain summits. Another component, basalt, originated from undersea lava vents. About 30 million years ago, the plate carrying the Pacific Ocean floor collided with the plate supporting the North American continent. As the heavy oceanic plate slid beneath the lighter continental plate, the upper layers of seabed jammed against the coastline, crumpling into what would become the Olympic Mountains. Glaciers and streams sculptured the mountains into their current profiles.
Glaciers nearly one mile thick also gouged out Puget Sound and Hood Canal to the east, and the Strait of Juan de Fuca to the north, isolating the peninsula from the mainland.
Ice Age isolation led to the 15 animals and 8 plants that evolved nowhere else on Earth, including the Olympic mountain milkvetch, Olympic marmot, Olympic Mazama pocket gopher, Olympic mud minnow, Beardslee, and crescent trout.
There are also the 11 mammals common in the nearby Cascades and Rockies that either died out in the Olympics or never found their way into the peninsula. The missing include the grizzly bear, lynx, and mountain sheep.
The mountain goats found here are non-native. They were introduced in the 1920s before the park was established. The goat population eventually boomed to over 1,000 and so damaged Olympic’s alpine meadows in 1981 the park staff began efforts to manage their numbers within the park.
Moist winds from the Pacific condense in the cool air of the Olympics and drop rain or snow, bestowing on the mountains' western slopes the wettest climate in the lower 48 states. Mount Olympus, which crowns the park at 2,400 metres, receives 500 centimetres of precipitation a year.