Beginning at a point on the boundary line between the states of South Dakota and Wyoming ten miles south of its intersection with the forty–fourth parallel of north latitude, the same being the northwest corner of Custer County, thence east in a direct line and along the north boundary of Custer County to the center of the main channel of the south fork of the Cheyenne River; thence southerly and up the center of the main channel of said river to its intersection with the northerly boundary of the Pine Ridge Indian Reservation; thence east and along said boundary line of said reservation to its intersection with the center of the main channel of White River; thence easterly and down the center of the main channel of White River to the range line between ranges seventeen and eighteen east Black Hills meridian; thence north and along said range line to the center of the main channel of the Cheyenne River; thence westerly up and along the center of the main channel of said river to its junction with the Belle Fourche River; thence southerly up and along the center of the main channel of the south fork of the Cheyenne River to the boundary line between Meade and Pennington counties; thence west and along said boundary line and along the boundary line between Pennington and Lawrence counties to the boundary line between the states of South Dakota and Wyoming; thence south and along said state line to the place of beginning.

Source: SL 1874-5, ch 29; PolC 1877, ch 42; SL 1897, ch 44, § 3; SDC 1939, § 12.0153.