Beginning at the southwest corner of township one hundred fifty-nine north, range seventy-three west of the fifth principal meridian; thence east along the line between townships one hundred fifty-eight and one hundred fifty-nine north to the southeast corner of township one hundred fifty-nine north, range sixty-nine west; thence north along the line between ranges sixty-eight and sixty-nine west to the northeast corner of township one hundred sixty north, range sixty-nine west, a point on the fifteenth standard parallel; thence west along the fifteenth standard parallel to the southeast corner of township one hundred sixty-one north, range sixty-nine west; thence continuing north along the line between ranges sixty-eight and sixty-nine west to the international boundary line between the United States and Canada; thence west along the international boundary line to the line between ranges seventy-three and seventy-four west; thence south along the line between ranges seventy-three and seventy-four west to the southwest corner of township one hundred sixty-one north, range seventy-three west, a point on the fifteenth standard parallel; thence east along the fifteenth standard parallel to the northwest corner of township one hundred sixty north, range seventy-three west; thence continuing south along the line between ranges seventy-three and seventy-four west to the point of beginning.