Panthers, cougars, pumas, catamounts, and mountain lions are all jus different names for one species, Puma Concolor. So depending on your proximity to mountains, it could very well have been one coming down in search of food. Granted there are subspecies, but all North American pumas are considered to be part P. c. Cougar, even Florida panthers.
Damn, I just realized my science side has been showing.