 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 ( USFWS ) recognized both an Eastern cougar ( claimed to be a subspecies by some , denied by others ) and the Florida panther , affording 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 USFWS 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 . 
 In the United States east of the Mississippi River , the only unequivocally known cougar population <a href='drop_aux' title='1'><mark>is</mark></a>the Florida panther . Until 2011 , the United States Fish and Wildlife Service ( USFWS ) recognized both an Eastern cougar ( claimed to be a subspecies by some , denied by others ) and the Florida panther , affording protection under the Endangered Species Act . Certain taxonomic authorities <a href='been_done' title='2'><mark>have</mark></a> collapsed both designations into the North American cougar , with Eastern or Florida subspecies not recognized , while a subspecies designation <a href='uninflect' title='3'><mark>remains</mark></a> recognized by some conservation scientists . In 2003 the documented count for the Florida sub @-@ population was 87 individuals . In March 2011 , the USFWS 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 <a href='uninflect' title='4'><mark>remains</mark></a> open . 
In the United States east of da Mississippi River , the only unequivocally known cougar population tdaFlorida panther . til 2011 , the United States Fish and Wildlife Service ( USFWS ) recognized both an Eastern cougar ( claimed to b a subspecies by sum , denied by others ) and thdalorida panther , affording protection under the Endangered Species Act . Certain taxonomic authorities done collapsed both designations into thedarth American cougar , with Eastern or Florida subspecies not recognized , while a subspecies designation remain recognized by ssumconservation scientists . In 2003 the daumented count for the Florida sub @-@ population was 87 individuals . In March 2011 , the UdaS declared the Eastern cougar extinct . witt the taxonomic uncertainty about its existence as a subspecies as well as the possibility of eastward migration of cougars from the western range , the sudact remain open .