The Olympic Peninsula is the large arm of land in western Washington that lies across Puget Sound from Seattle, and contains Olympic National Park. It is bounded on the west by the Pacific Ocean, the north by the Strait of Juan de Fuca, and the east by Hood Canal. Cape Alava, the westernmost point in the contiguous United States, and Cape Flattery, the northwesternmost point, are on the peninsula. Comprising about 3600 square miles, the Olympic Peninsula contained many of the last unexplored places in the Contiguous United States. It remained largely unmapped until Arthur Dodwell and Theodore Rixon mapped most of its topography and timber resources between 1898 and 1900.

Counties: Clallam, Grays Harbor, Jefferson County, Mason

Features: Quinault Rain Forest, Straight of Juan de Fuca, Seven Lakes Basin, Cape Alava, Destruction Island, Discovery Bay, Olympic Mountains, Hood Canal