* Igloo - Igloos are domed structures made of snow or ice that are used as shelters by the Inuit people of the Arctic. There are a few igloos in South Dakota that can be visited by tourists.
* Indian reservations - South Dakota is home to nine Indian reservations, which are areas of land that are set aside for the use of Native American tribes.
* Iowa - Iowa is a state that borders South Dakota to the east. The two states are separated by the Missouri River.
* Iron - Iron is a metal that is found in South Dakota. It is used to make steel, which is used in the construction of bridges, buildings, and other structures.
