Lieutenant Zebulon Pike was charged with exploring the Mississippi River from St. Louis, Missouri, to its source in Minnesota after this area was bought as part of the Louisiana Purchase. When Pike and his men reached what is now Morrison County in October 1805, winter weather forced them to build a fort near this site. The men lived here for two months before Pike continued upriver with some of his contingent. On the trip downriver, Pike returned to the fort, fetched the men left behind, and the expedition arrived back in St. Louis on April 30, 1806.