Olympic National Park encompasses 922,651 acres (over 1,400 square miles) in the center of Washington’s Olympic Peninsula and along a 60 mile strip of wilderness coastline on the Pacific Ocean. The park is located less than 116 kilometers (72 miles) west/northwest of the Seattle-Tacoma area (36 miles as the crow flies). The park receives over 5 million visits per year, most from the state of Washington. Over 96% of the park is designated as wilderness.
From sea level, the park rises to almost 8000 feet at Mount Olympus in less than 40 miles. The Olympic Mountains intercept moisture-laden Pacific winds, resulting in a rainshadow effect more pronounced than any other in North America. Olympic National Park is the wettest spot in the conterminous United States. The west slopes of Mount Olympus receive about 200 inches of precipitation per year, while less than 34 miles to the east, precipitation is under 20 inches per year.
The park’s biotic diversity mirrors its climatic diversity. Park ecosystems range from the rich intertidal zone, to rainforests, montane forests, alpine meadows, and glaciers. Temperate rainforests blanket the western slopes of the mountains, while alpine tundra conditions prevail in the dry, northeast section of the park. Along this gradient, Sitka spruce, Western red cedar, and Western hemlock yield to subalpine fir, white pine, and lodgepole pine.
Although they occur as a separate, higher and more rugged mountain massif, geologically, the Olympic Mountains are closely related to the Coast Range of Oregon. The predominant rock types of the Olympics are sandstone, shale, and basalt. Most rocks of the Olympic Mountains were formed on the bed of the Pacific Ocean, and later uplifted to form a “disorganized, circular array of jagged peaks” . These mountains formed during a separate uplift event, rather than as part of the long coastal mountain chain. Eleven major rivers radiate from the mountainous core of the park. Within these watersheds lie over 260 glaciers and over 400 lakes and wetlands.
During glacial periods of the Pleistocene, the Olympic Mountains were cut off from the continent. This island-like isolation fostered high levels of endemism among plant and animal communities of the Peninsula. There are thirty five (35) endemic forms of plants and animals currently recognized on the Olympic Peninsula, including 15 endemic plants, 1 amphibian, 3 fish, and 5 mammals. Largely due to habitat alterations (or harvest activities) outside park boundaries, there are also 10 federally listed threatened or endangered species within the park, including 5 birds, 4 fish, and 1 insect species. At least one species, the gray wolf, is known to be extirpated. Another species, the fisher, is also suspected to be extinct within the park.
The park is recognized as both a World Heritage Site, and an International Biosphere Reserve. In its review of the park's nomination as a world heritage site, the International Union for the Conservation of Nature concluded that: "Olympic National Park is the best natural area in the entire Pacific Northwest, with a spectacular coastline, scenic lakes, majestic mountains and glaciers, and magnificent temperate rain forests; these are outstanding examples of on-going evolution and superlative natural phenomena. It is unmatched in the world."