The Northwestern-most state of the contiguous United States. Its northern border lies mostly along the 49th parallel, and then via marine boundaries through the Strait of Georgia, Haro Strait and Strait of Juan de Fuca, with the Canadian province of British Columbia to the north. Washington borders Oregon to the south, with the Columbia River forming most of the boundary and the 46th parallel forming the eastern part of the southern boundary. To the east Washington borders Idaho, bounded mostly by the meridian running north from the confluence of the Snake River and Clearwater River, except for the southernmost section where the border follows the Snake River. To the west of Washington lies the Pacific Ocean.