Fort Belknap Agency

Fort Belknap is home to two nations, the Aaniiih, called Gros Ventre in the treaties and in the 1908 case, and the Nakoda, called Assiniboine. The reservation was set aside in 1888 by an agreement that traded away a far larger country for this much smaller one, with the Milk River as its northern line. In 1889 the government put up its agency buildings on the reservation, and the people who lived and worked there drew everything from the river: water to drink, to cook with and to irrigate the fields the tribes were being pressed to farm.

In 1900 settlers upstream, some of them on land the tribes had given up in the 1888 agreement, built dams, reservoirs and ditches and took the Milk River before it reached the reservation. The United States sued on the tribes' behalf. The settlers' defense was the West's rule of first in time: they had put the water to use first, and the agreement said nothing about water at all. On January 6, 1908, in Winters v. United States, the Supreme Court held that when the tribes gave up their country and kept a reservation on dry land, water enough to make it a home had been kept with it. That right dated from the day the reservation was made, and unlike a settler's right it could not be lost by going unused. A water historian later found in the census that the lead appellant, Henry Winters, was really Henry Winter.

The doctrine named for him now stands behind tribal water claims across the West, and it began on this stretch of the Milk River. The agency, the seat of the Fort Belknap Indian Community's government, sits on U.S. 2 just southeast of Harlem.