Columbia River Basalt Group
- Adams County, Washington
- Asotin County, Washington
- Benton County, Washington
- Chelan County, Washington
- Clallam County, Washington
- Clark County, Washington
- Columbia County, Washington
- Cowlitz County, Washington
- Douglas County, Washington
- Ferry County, Washington
- Franklin County, Washington
- Garfield County, Washington
- Grant County, Washington
- Grays Harbor County, Washington
- Island County, Washington
- Jefferson County, Washington
- King County, Washington
- Kitsap County, Washington
- Kittitas County, Washington
- Klickitat County, Washington
- Lewis County, Washington
- Lincoln County, Washington
- Mason County, Washington
- Okanogan County, Washington
- Pacific County, Washington
- Pend Oreille County, Washington
- Pierce County, Washington
- San Juan County, Washington
- Skagit County, Washington
- Skamania County, Washington
- Snohomish County, Washington
- Spokane County, Washington
- Stevens County, Washington
- Thurston County, Washington
- Wahkiakum County, Washington
- Walla Walla County, Washington
- Whatcom County, Washington
- Whitman County, Washington
- Yakima County, Washington
eastbound on Interstate 90
longest river entirely in the state
- Washington (state) (Wikipedia)
Washington (/ˈwɒʃɪŋtən/), officially the State of Washington and often referred to as Washington state to distinguish it from the national capital, Washington, D.C., is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington Territory, which was ceded by the British Empire in 1846, by the Oregon Treaty in the settlement of the Oregon boundary dispute. The state is bordered on the west by the Pacific Ocean, Oregon to the south, Idaho to the east, and the Canadian province of British Columbia to the north. It was admitted to the Union as the 42nd state in 1889. Olympia is the state capital; the state’s largest city is Seattle.
