On This Date in Minnesota History: February 13

February 13, 1857 – Established on this date, Isanti County, Minn., “bears the former name, now obsolete, of a larger division of the Dakotas or Sioux, anciently Izatys, now Santees, who lived two hundred years ago in the region of the Rum river and Mille Lacs, called by Hennepin respectively the river and lake of the Isantis.”

Upham, Warren; Minnesota Geographic Names, Their Origin and Historic Significance; Minnesota Historical Society (St. Paul, Minn., 1969); p. 249.

http://mn-isanti.manatron.com/