km2) of Knox County, Nebraska to the Ponca, and about half the tribe moved back north from Indian Territory. The tribe continued to decline. In the 1930s, the University of Nebraska and the Smithsonian Institution conducted an archeological project to identify and save prehistoric artifacts before they were destroyed during agricultural development. The team excavated a prehistoric Ponca village, which included large circular homes up to sixty feet in diameter, located almost two miles (3 km) along the south bank of the Niobrara River. After World War II, the US government began a policy of terminating its relationship with tribes. In 1966, the US federal government terminated the tribe (then called the Northern Ponca). It distributed its land by allotment to members, and sold off what it called surplus. Many individuals sold off their separate allotments over the decades, sometimes being tricked by speculators. In the 1970s, the tribe started efforts to reorganize politically. Members wanted to revive the cultural identity of its people and improve their welfare. First, they sought state recognition and then allied with their Congressional representatives to seek legislation for federal recognition. On October 31, 1990, the Ponca Restoration Bill was signed into law, and they were recognized as the Ponca Tribe of Nebraska. They are now trying to rebuild a land base on their ancestral lands. They are the only federally recognized tribe in Nebraska without a reservation. Today the Ponca Tribe of Nebraska has over 2,783 enrolled members and is headquartered in Niobrara, Nebraska. Oklahoma After the 1877 forced relocation onto the Quapaw Reservation in Indian Territory, the tribe moved west to their own lands along the Arkansas and Salt Fork Rivers. The full-bloods formed a tipi village, while the mixed-bloods settled about Chikaskia River. During opposition by Ponca leadership, the US government began dismantling tribal government under the Curtis Act. In an attempt to encourage assimilation (and to allow Oklahoma to become a state), they allotted reservation lands to individual members under the Dawes Act in 1891 and 1892. Any land remaining after allotment was made available for sale to non-natives. After Oklahoma achieved statehood, some remaining Ponca land was leased or sold to the 101 Ranch, where many Ponca people found employment. The 1911 discovery of oil on Ponca lands provided revenues but had mixed results. There were environmental disasters as oil refineries dumped waste directly into the Arkansas River. In 1918,