Wash. Rev. Code § 36.04.020
Asotin county shall consist of the territory bounded as follows, to wit: Commencing at a point in the channel of Snake river on the township line between ranges forty-four and forty-five east, Willamette Meridian; thence running south to the northwest corner of section thirty, township eleven north, range forty-five east, Willamette Meridian; thence west six miles; south one mile; west two miles; south one mile; west one mile to the northwest corner of section three in township ten north, of range forty-three east, Willamette Meridian; thence south eighteen miles; thence west three miles; thence south to the Oregon line; thence east on said line to the midchannel of Snake river; thence down the midchannel of Snake river to the place of beginning.
RCW 36.04.020