Marquette and Joliet explore parts of Iowa and make the first maps of the Lakes Region from Indian descriptions. The first recognition of the Iowa Great Lakes appeared in the Wllliam Delisle's map of 1718. Iowa territory now belongs to United States. Lewis and Clark explore Missouri river. Indians describe our lakes to them.
Many trappers visit the lakes but leave no written record.
John C. Fremont explores the lakes for the government. He was a famous Union general and also ran for President. Iowa admitted to the Union. Governor Hampton approved an act creating 50 new counties including Dickinson County. Treaty of Mendota by which the Yankton Sioux relinquished their claim of land in northwest Iowa and nearby areas.