In 1913, school children playing on a hillside near Fort Pierre discovered an inscribed lead plate that had been buried there in 1743 by the Verendrye brothers. The plate is the first written record of the visit of Europeans to South Dakota.
According to a journal found in the French archives, two sons of Pierre Gaultier de Varennes, sieur de La Vérendrye, led an expedition in 1742-1743 across the northern Great Plains in an effort to reach the Pacific Ocean. The Verendrye Brothers documented the secret placement of a 8 1/2″ by 6 1/2″ lead plate bearing the French coat of arms and text in Latin about the King of France on a bluff overlooking the Missouri River. They told the local Native Americans that the cairn they built over the site was a memorial of their passage, but it marked their claim of the territory for France.