Olympic National Forest is a U.S. National Forest located in Washington, USA. With an area of 628,115 acres (2,541.89 km²), it nearly surrounds Olympic National Park and the Olympic Mountain range. Olympic National Forest contains parts of Clallam, Grays Harbor, Jefferson, and Mason counties. The landscape of the national forest varies, from the temperate Olympic rain forest to the salt water fjord of Hood Canal to the peaks of Mt.