Knife Lake is in Isanti County Prof. A. W. Williamson wrote of this word, and of its probable derivation from the Dakota name of Knife Lake in Kanabec County: "Isanti (isanati or isanyati),--isan, knife; ati, dwell on or at; the Dakota name of the part of the nation occupying Minnesota, and comprising the Sissetons as well as those now known as Santees; it is supposed the name was given as this lake was their chief location for a time on their westward journey." From: Upham, Warren. Minnesota Place Names: A Geographical Encyclopedia. St. Paul, MN: Minnesota Historical Society Press, First edition 1920. Third Edition 2001. Print.