The county of Keya Paha is bounded as follows: Commencing in the middle of the channel of the Niobrara River where the line dividing ranges sixteen and seventeen, west, of sixth principal meridian crosses said Niobrara River; thence north to the forty-third parallel of north latitude; thence west along said parallel of north latitude to the line dividing range twenty-four from range twenty-five, west, of sixth principal meridian; thence south along said line to the middle of the channel of the Niobrara River; thence down the middle of the channel of the Niobrara River to the place of beginning.