Puma That Vanished from U.S. East Coast 80 Years Ago Sadly Declared Extinct
Local Mountain Lion Population Faces Precipitous Decline in Genetic Diversity Within 50 Years, Possible Extinction - Santa Monica Mountains National Recreation Area (U.S. National Park Service)
North American cougar - Wikipedia
This Isn't the End of the Eastern Cougar - Outside Online
Now Extinct, Eastern Cougar Removed From Endangered List | Courthouse News Service
The eastern puma is declared officially extinct | Daily Mail Online
Threats - WildFutures
Eastern puma declared extinct, 80 years after last confirmed sighting - The Wildlife Society