Beginning at the intersection of the main channel of the Missouri River with the ninth standard parallel; thence east along the ninth standard parallel to the southeast corner of township one hundred thirty-seven north, range seventy-five west of the fifth principal meridian; thence north along the line between ranges seventy-four and seventy-five west to the northeast corner of township one hundred forty north, range seventy-five west, a point on the tenth standard parallel; thence west along the tenth standard parallel to the southeast corner of township one hundred forty-one north, range seventy-five west; thence continuing north along the line between ranges seventy-four and seventy-five west to the northeast corner of township one hundred forty-four north, range seventy-five west, a point on the eleventh standard parallel; thence west on the eleventh standard parallel to the northwest corner of township one hundred forty-four north, range seventy-nine west; thence south along the line between ranges seventy-nine and eighty west to the southwest corner of township one hundred forty-three north, range seventy-nine west; thence west along the line between townships one hundred forty-two     and one hundred forty-three north to the main channel of the Missouri River; thence in a southerly direction along the main channel of the Missouri River to the point of beginning.