stylistic:tone, structural:reformatting, quality:corruption, stylistic:style_transfer, structural:expansion
Ethnic and modern geographical divisions

The Sioux are divided into three ethnic groups, the larger of which are divided into sub-groups, and further branched into bands. The earliest known European record of the Sioux identified them in Minnesota, Iowa, and Wisconsin. After the introduction of the horse in the early 18th century, the Sioux dominated larger areas of land—from present-day Central Canada to the Platte River, from Minnesota to the Yellowstone River, including the Powder River country.

The Sioux maintain many separate tribal governments scattered across several reservations and communities in North America: in the Dakotas, Minnesota, Nebraska, and Montana in the United States; and in Manitoba, and southern Saskatchewan in Canada. Today, many Sioux also live outside their reservations.