The Lower Sioux Indian Reservation, (Dakota: Cansa'yapi; Lakota: Čhaŋšáyapi) also known as the Mdewakanton Tribal Reservation, is an Indian reservation located along the southern bank of the Minnesota River in Paxton Township and Sherman Township, Redwood County, Minnesota. It lies east of the city of Redwood Falls, and just south of Morton. The land became part of a reservation after the signing of the Treaty of Traverse des Sioux in 1851, but has now shrunk to a very small size.