Idaho Code § 31-116
Canyon county is described as follows: beginning at a point in the middle of the channel of Snake river, where the line between township one (1) south, range one (1) west, and township one (1) south, range two (2) west, crosses said river;
Eastern boundary. Thence north to the northwest corner of township one (1) north, range one (1) west; thence east to the southeast corner of section thirty-two (32), township two (2) north, range one (1) west; thence north to the northwest corner of section four (4), township three (3) north, range one (1) west; thence west to the northwest corner of township three (3) north, range one (1) west; thence north to the northwest corner of township five (5) north, range one (1) west (R.C., section 23h);
Northern boundary. Thence west on the township line between townships five (5) and six (6), to the southwest corner of section thirty-one (31), township six (6) north, range three (3) west (1915, ch. 165, section 2, p. 363; 1917, ch. 11, section 2, p. 15); thence south on range line between ranges three (3) and four (4), one-half (1/2) mile to the east quarter corner of section one (1), township five (5) north, range four (4) west; thence west along the center line of sections one (1) and two (2), said township and range, two (2) miles to the east quarter corner of section three (3), said township and range; thence south along the section line one-half (1/2) mile to the southeast corner of section three (3), said township and range; thence west along the section line three (3) miles to the southwest corner of section five (5), said township and range; thence north along the section line one (1) mile to the northwest corner of section five (5), said township and range; thence west along the township line between townships five (5) and six (6) north, two (2) miles to the southwest corner of section thirty-six (36), township six (6) north, range five (5) west; thence north along the section line one (1) mile to the northwest corner of section thirty-six (36), said township and range; thence west along the section line one (1) mile to the southwest corner of section twenty-six (26), said township and range; thence north along the section line one (1) mile to the southwest corner of section twenty-three (23), said township and range; thence west along the section line two (2) miles to the southwest corner of section twenty-one (21), said township and range; thence north along the section line three (3) miles to the northwest corner of section nine (9), said township and range; thence west along the section line one and one-half (1 1/2) miles, more or less, to an intersection with the west line of the state of Idaho (1917, ch. 11, section 2, p. 15);
Western boundary. Thence up the middle of the channel of Snake river to the boundary line between Idaho and Oregon; thence south along the boundary line between Idaho and Oregon to the middle of Snake river;
Southern boundary. Thence up the middle of the channel of Snake river to the place of beginning (R.C., section 23h).
County seat-Caldwell.
Idaho Code § 31-116