In September 1805, Lt. Zebulon Pike led 20 soldiers north from St. Louis, MO, on an expedition to locate the headwaters of the Mississippi River, acquired a year earlier as part of the Louisiana Purchase. River levels and inclement weather slowed their progress, and by the time they reached the Swan River, eight miles south of Little Elk, the men were exhausted and some could go no further. After building a fort at Swan River, Pike continued his mission with 12 men. The sergeant commanding the fort, convinced Pike would not survive, sold, traded, or used most of the company's provisions and many of Pike's personal effects. When Pike returned to the fort in March 1806, the sergeant was lashed and demoted. On August 7, 1836, explorer Joseph Nicollet took an astronomical reading near here to determine the geographical location of Little Elk River. Nicollet also took readings at Little Falls, Crow Wing, and other notable places, and he used this data to draw the first accurate map of the Upper Mississippi, published in 1842.