Which river, flowing south from Lake Itasca in Minnesota, was identified by Henry Schoolcraft in 1832 as the headwaters of the nation's longest river system?

• A Missouri River
• B Ohio River
• C St. Croix River
• D Mississippi River ✓

Lake Itasca, a small glacial lake in Itasca State Park, was identified as the Mississippi's headwaters by Henry Schoolcraft in 1832, who combined the Latin words veritas and caput.