Section 41-12-202 - Definitions(a) As used in this compact: (i) The term "Belle Fourche River" shall mean and include the Belle Fourche River and all its tributaries originating in Wyoming; (ii) The term "basin" shall mean that area in South Dakota and Wyoming which is naturally drained by the Belle Fourche River, and all its tributaries; (iii) The term "beneficial use" is herein defined to be that use by which the water supply of a drainage basin is depleted when usefully employed by the activities of man, and includes water lost by evaporation, and other natural causes from streams, canals, ditches, irrigated areas, and reservoirs; (iv) Where the name of the state or the term "state" or "states" is used, these shall be construed to include any person or entity of any nature whatsoever using, claiming, or in any manner asserting any right to the use of the waters of the Belle Fourche River under the authority of that state.