Dispossession to diminishment: The Yankton Sioux Reservation, 1858-1998

On January 26, 1998, the United States Supreme Court diminished the size of Yankton Sioux Reservation in South Dakota by roughly forty percent ( State of South Dakota v. Yankton Sioux Tribe). The diminishment decision capped off more than one hundred and seventy years of dispossession of the Yanktons\u27 land base and political sovereignty. The Yanktons\u27 430,405 acre Reservation was established in 1858 when they agreed to cede aboriginal title to more than eleven million acres in what is now eastern South Dakota. In return for their cession, the Yanktons were provided a reservation, annuities, and services. Consistent with the prevailing federal Indian policy of the day, the Reservation was allotted in severalty in the 1890s. After individual allotments were made, the remaining “surplus” lands were ceded back to the federal government (168,000 acres), resulting in a “checkerboarded” pattern of Indian and non-Indian land ownership. The 1998 Supreme Court decision held that the surplus lands (those ceded back to the government), no longer constituted Indian Country—under the meaning of the law. This study analyzes the relationship of the historical dispossession of the Yankton Sioux land base to the subsequent diminishment of their Reservation. The current spatial patterns of land ownership and the previous checkerboarding of the Reservation are the most important contributing factors to the current jurisdictional configuration on the Yankton Reservation. This study considers the entire span of Yankton dispossession in the nineteenth and twentieth centuries; with special emphasis on the process and impact of the alienation of the Yanktons\u27 allotments, the jurisdictional consequences of reservation diminishment, and whether that diminishment has eroded the Yanktons\u27 political sovereignty. Finally, this study examines the precedent this case has established for the remainder of Indian Country and whether the actual composition of the Supreme Court is a salient factor in the diminishment of the Yankton Sioux Reservation