This collection consists of material accumulated by Hans L. Billie during his tenure as Montana's surface water rights coordinator. The collection is divided into two series. The subject files (1937-1968, undated) consist of material related to the Flathead Irrigation Project, the "Fort Belknap Indian Irrigation District", the Tongue River Project, and the Yellowstone River Compact. The miscellany 1941, 1954-1955, 1971-1973, undated) consists of lists of the decreed water rights in the various Montana counties (excluding Blaine, Carter, Daniels, Dawson, Treasure, and Wibaux) a United States Bureau of Reclamation annual project history for the Milk River Project, and various documents relating to Montana water law and rights.