ARTICLE 24, SECTION 1
SECTION 1 STATE BOUNDARIES. The boundaries of the state of
Washington shall be as follows: Beginning at a point in the
Pacific ocean one marine league due west of and opposite the
middle of the mouth of the north ship channel of the Columbia
river thence running easterly to and up the middle channel of
said river and where it is divided by islands up the middle of
the widest channel thereof to where the forty-sixth parallel of
north latitude crosses said river near the mouth of the Walla
Walla river; thence east on said forty-sixth parallel of latitude
to the middle of the main channel of Shoshone or Snake river,
thence follow down the middle of the main channel of Snake river
to a point opposite the mouth of the Kooskooskia or Clear Water
river, thence due north to the forty-ninth parallel of north
latitude, thence west along said forty-ninth parallel of north
latitude to the middle of the channel which separates Vancouver's
island from the continent, that is to say to a point in longitude
123 degrees, 19 minutes and 15 seconds west, thence following the
boundary line between the United States and British possessions
through the channel which separates Vancouver's island from the
continent to the termination of the boundary line between the
United States and British possessions at a point in the Pacific
ocean equidistant between Bonnilla point on Vancouver's island
and Tatoosh island light house, thence running in a southerly
course and parallel with the coast line, keeping one marine
league off shore to place of beginning; until such boundaries are
modified by appropriate interstate compacts duly approved by the
Congress of the United States. [AMENDMENT 33, 1957 Senate Joint
Resolution No. 10. Approved November 4, 1958.]