Traverse des Sioux, in the Minnesota River valley formed by glacial meltwaters more than 10,000 years ago, was for centuries a crossroads where Dakota people gathered to hunt game and exchange goods and information, and by 1700 Europeans had joined them to trade guns, cloth, and other products for furs. The Dakota called the nearby shallow, hard-bottomed river crossing Oiyuwege, meaning "the place of crossing," while French explorers renamed it Traverse des Sioux, or "crossing place of the Sioux," though the exact location of the crossing is now unknown. The Dakota, known to outsiders as the Sioux, had lived here for centuries, and the Eastern branch of the Dakota Nation, also called the Santee, included the Mdewakanton, Wahpekute, Wahpeton, and Sisseton bands. Early French and English explorers called this waterway the St. Pierre (St. Peter) River, but in 1852 the territorial legislature petitioned the U.S. government to change its name to Minnesota, a Dakota word meaning cloudy water. As settlers in the newly established Minnesota Territory pressed to open Indian lands for settlement, a treaty signed here on July 23, 1851 transferred about 21 million acres of Dakota land in southwestern Minnesota to the U.S. government for about 7.5 cents per acre and led to the Sisseton and Wahpeton bands' movement to reservation lands along the Minnesota River. The sale triggered a land rush, and by 1853 this historic meeting place had become the town of Traverse des Sioux, but it soon failed; the site was farmed until 1969, then became a state park, and in 1973 it was listed on the National Register of Historic Places and designated a state historic site.