Armstrong County : Created by Dakota Territory as Pyatt County in 1883 from Cheyenne, Rusk, and Stanley Counties. Renamed Armstrong in 1895. The western half was annexed to form part of the second Ziebach County, in 1911. The remainder was annexed into Dewey in 1952.
Ashmore County
Big Sioux County
Bramble County
Bruguier County
Burchard County
Burdick County
Cheyenne County
Choteau County: Abolished when it merged into Perkins County along with Martin, Rinehart and Wagner Counties.
Cole County: organized in 1862, was named for Austin Cole, who was a member of the first Territorial Legislature. Two years later, the boundaries were rearranged and the name changed to Union because of sentiment for the Union side of the civil war.
Cragin County
Delano County: Absorbed by Meade County
Ewing County : Created upon statehood. Abolished one year later, when it became the northern half of Harding County.
Forsythe County
Greely County, South Dakota
Jayne County
Lugenbeel County : Created by Dakota Territory from unorganized lands and Meyer and Pratt Counties in 1875. Abolished in 1909 when it became part of Bennett and Todd Counties.
Martin County: Abolished when it merged into Perkins County along with Choteau, Rinehart and Wagner Counties.
Pyatt County : Created by Dakota Territory from unorganized lands in 1883. Renamed Armstrong in 1895. Later divided between the revived Ziebach County and Dewey County.
Rinehart County: Abolished when it merged into Perkins County along with Choteau, Martin, and Wagner Counties.
Schnasse County : Created by Dakota Territory from unorganized lands and part of Boreman County in 1883. Later absorbed into Boreman and the revived Ziebach Counties
Scobey County: Absorbed by Meade County
Sterling County : Created by Dakota Territory from Cheyenne County. Abolished in 1911 when it became part of Haakon and Ziebach Counties
Wagner County: Abolished when it merged into Perkins County along with Choteau, Martin, and Rinehart Counties.
Washabaugh County : South Dakota's most recent county to be eliminated. Created by Dakota Territory in 1883. Abolished in 1983 when it was merged with Jackson County.
Washington County : Abolished in 1943 when it was divided between Pennington and Shannon Counties.
Ziebach County : Created in 1889, upon statehood. Abolished in 1890, becoming the eastern portion of Pennington County. The name was revived in 1911, when a second Ziebach County was created from parts of Sterling, Schnasse and Pyatt Counties.
