(claimants’ predecessor first perfected a water right in 1904 for surface water from a creek to be applied by flood irrigation on a maximum of 645 acres; the Department of Natural Resources and Conservation published issue remarks noting that aerial photographs of claimants’ property from 1962 and 1978 appeared to indicate “0 acres irrigated”; the State of Montana joined in an action before the Water Master, seeking summary judgment declaring the water right abandoned; the Water Master concluded that the water right had been abandoned, but the Water Court reversed; in affirming the Water Court’s holding, the Court ruled that the standard from 79 Ranch v. Pitsch, 204 Mont. 426, 666 P.2d 215 (1983)—a long period of nonuse raises a rebuttable presumption of intent to abandon—did apply to pre-1973 existing water rights; however, the record supported the Water Court’s determination that the claimants submitted sufficient evidence to overcome the presumption of abandonment).