However, turns out there never was such an animal distinct from the Western cougar-
The U.S. Fish and Wildlife Service this week said the eastern cougar was extinct, and said it should be taken off the endangered species.
However, it turns out most think the Eastern cougar was a distinction that made no difference because there never was a kind of cougar or mountain lion in the East any different from the increasingly common cougar of the Western United States which is reclaiming its territory in the Midwest and the East at a pretty good rate.
The debate between “lumpers” and “splitters” has been common among biologists studying species and sub-species. A lumper would say the so-called “eastern cougar never did differ significantly from other cougar in the United States. A similar controversy has of course been part of the restoration of the gray wolf to the Western United States, the Great Lakes and the red wolf of the Carolinas. The latter is very similar to the wolves of eastern Canada in Quebec Province.
U.S. Declares Eastern Cougar Extinct, With an Asterisk. By Felicity Barringer. New York Times.