South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of 77,116 square miles (199,730 km2) and an estimated population of just over 800,000.Pierre is the state capital and Sioux Falls, with a population of nearly 160,000, is South Dakota's largest city. South Dakota is bordered by the states of North Dakota, Minnesota, Iowa, Nebraska, Wyoming, and Montana. The state is bisected by the Missouri River, dividing South Dakota into two geographically and socially distinct halves, known to residents as "East River" and "West River". Eastern South Dakota is home to most of the state's population, and fertile soil in this area is used to grow a variety of crops.
West of the Missouri, ranching is the predominant agricultural activity, and the economy is more dependent on tourism and defense spending. The Black Hills, a group of low pine-covered mountains, is located in the southwest part of the state. The Black Hills are sacred to the Sioux. Mount Rushmore, a major tourist destination, is located there. Other attractions in the southwest include Badlands and Wind Cave national parks, Custer State Park, the Crazy Horse Memorial, and historic Deadwood. South Dakota experiences a temperate continental climate, with four distinct seasons and precipitation ranging from moderate in the east to semi-arid in the west. The ecology of the state features species typical of a North American grassland biome.