Map shows red colored areas being oak wilt infected or killed; 500 of 1,100 acres of upland oak forest dead or dying of oak wilt disease. At University of Minnesota's Cedar Creek Ecosystem Science Reserve. One of the 3 largest oak wilt disease "Reservoirs" in Minnesota. Oak wilt disease delineation based on DNR 2007 color infrared photos and NRCS soils maps. This version shows the Isanti - Anoka county line.