There is a large invasion of great gray and hawk owls into northern
Minnesota.  See Minnesota Ornithologist's Union web site,
http://www.cbs.umn.edu/-mou/ for info.  The Sunday Minneapolis Star Tribune
had a full page article on December 26, Section C 16.  My brother from
Minneapolis birded yesterday for only 1 hour and saw 9 great grays and 1
hawk owl.  The birds are in trees right next to roads.  It is expected the
owls will stay for the rest of the winter.