Miss. Code Ann. § 19-1-33

De Soto County is bounded by beginning where the northern boundary of the state intersects the Mississippi River; thence east with said boundary line to the center of range five, west; thence south with the section lines through the center of said range to the southeast corner of section thirty-two, township three, range five, west; thence west on the township line between townships three and four to where said line intersects Coldwater River; thence down, with the meanderings of said river, to where the range line between ranges nine and ten intersects said river; thence north along said range line to the lines between townships two and three, range nine, west; thence west with said township line to the Mississippi River; thence up said river to the beginning. The county site is Hernando.