South Dakota

Friends and allies

South Dakota takes its name from Dakota Territory, which was named for the Dakota people, part of the group often called the Sioux. In the Dakota language the word Dakhóta means “friend” or “ally”; related forms are Lakhóta and Nakhóta. The “South” simply marks the southern half of the territory, which was split in two at statehood.

Two states, one day

Dakota Territory’s capital was Yankton, in what is now South Dakota, from 1861, and Bismarck, now in North Dakota, from 1883. In 1889 the territory was divided, and both halves were admitted on November 2. President Benjamin Harrison shuffled and covered the two proclamations so that no one would know which he had signed first. South Dakota is counted as the 40th state only because it comes second in the alphabet.

Pierre

When South Dakotans adopted their constitution on October 1, 1889, they also chose Pierre as the temporary capital. Its backers pointed to its central location and its place on the Missouri River. Voters made it the permanent capital over Huron in 1890 and confirmed it again over Mitchell in 1904, after a hard-fought campaign. Pierre’s Capitol, dedicated in 1910, uses a design similar to Montana’s. The capital page tells the story.

Rushmore and sunshine

South Dakota has had several nicknames: the Sunshine State, the Coyote State and, since 1992, its official nickname, the Mount Rushmore State, for the sculpture in the Black Hills. The same 1992 law put the new nickname on the state flag, replacing “The Sunshine State,” which had been there since 1909. The flag still shows a blazing gold sun around the state seal. The motto, “Under God the People Rule,” is part of the seal and the state constitution.

Pheasants, pasque flowers and chislic

South Dakota has 24 official state symbols. The ring-necked pheasant, an Asian bird first released successfully in the state in 1908, is the state bird, and the pasque flower, one of the first prairie flowers of spring, the state flower, with its own motto, “I Lead.” The Black Hills spruce is the state tree and the coyote the state animal. The state fossil is Triceratops, Black Hills gold the state jewelry, and food symbols include kuchen, fry bread and chislic, the official state nosh. See them all on the South Dakota symbols page.

Land and people

South Dakota covers 77,116 square miles, 17th among the states, but it had only about 935,000 residents in 2025, 46th in the country and up about 5 percent from 2020. It borders six states: North Dakota, Minnesota, Iowa, Nebraska, Wyoming and Montana. Sioux Falls, with about 214,000 people, is by far the largest city, followed by Rapid City, Aberdeen, Brookings and Watertown.