Prairie Island Indian Community is a Mdewakanton Sioux Indian reservation in Goodhue County, Minnesota, along the Mississippi River, in and around the city of Red Wing. It was created in 1889, with boundaries modified after that time. Much of the reservation land was lost following construction of Lock and Dam No. 3 along the river by the United States Army Corps of Engineers to improve navigation.
Later, the Prairie Island Nuclear Power Plant was built nearby. The community has grabbed headlines because of the decision to store radioactive waste in above-ground steel casks. The main reservation lies within the city of Red Wing, but there are off-reservation trust lands both within Red Wing and in Welch Township in northern Goodhue County, as well as in Ravenna Township in eastern Dakota County which nearly doubles the size of the reservation’s territory. The reservation had 199 residents as of the 2000 census, including its trust lands. Its total land area is 1.6689 sq mi (4.3225 km², or 1,068.1 acres). The tribe operates Treasure Island Resort & Casino near the Mississippi River north of Red Wing.