Klickitat county shall consist of the territory bounded as follows, to wit: Commencing at a point in the midchannel of the Columbia river opposite the mouth of the White Salmon river; thence up the channel of the White Salmon river as far north as the southern boundary of township four north, range ten east of Willamette Meridian; thence due west on the township line to range nine east of Willamette Meridian; thence north following said range line to where it intersects the south boundary of Yakima county projected; thence east along the north boundary of township six north until that line intersects the range line between range twenty-three east and range twenty-four east; thence south along such range line to the Columbia river; thence down the Columbia river, midchannel, to the place of beginning.