|South Dakota is among the US states with lowest population density. According to a 2008 estimate, the state has a population figure of just 804,194 residents, who live in an area of 77,116 square miles. As a result, the state has a population density of just 10.5 per square mile. Moreover, the state is the seventeenth largest by size among all states in the US. Situated in the the Midwestern region of the the country, South Dakota is bordered by North Dakota to the north, Iowa and Minnesota to the east, Wyoming and Montana to the west and Nebraska to the south. The Missouri river is the largest river in South Dakota that divides the state into two equal halves. Cheyenne, Big Sioux, White and James are the names of other important rivers in the state. The highest point is Harney Peak with a height of 7,242 feet and the lowest point is Big Stone Lake with a depth of 966 feet. South Dakota was admitted to the Union as the 40th state in 1889. The state is marked by agricultural economy and a rural lifestyle. Sioux Falls is the largest city and Pierre is the capital of the state.