 In the United States east of the Mississippi River , the only unequivocally known cougar population is the Florida panther . Until 2011 , the United States Fish and Wildlife Service ( <unk> ) recognized both an Eastern cougar ( claimed to be a subspecies by some , denied by others ) and the Florida panther , <unk> protection under the Endangered Species Act . Certain taxonomic authorities have collapsed both designations into the North American cougar , with Eastern or Florida subspecies not recognized , while a subspecies designation remains recognized by some conservation scientists . In 2003 the documented count for the Florida sub @-@ population was 87 individuals . In March 2011 , the <unk> declared the Eastern cougar extinct . With the taxonomic uncertainty about its existence as a subspecies as well as the possibility of eastward migration of cougars from the western range , the subject remains open . 
