Biologists estimate that 1,500 American Black Bears live in Great Smoky Mountains National Park. Gary Carter Photo. Over 700 miles of streams in the park support fish. The park boasts over 50 native fish species, including the brook trout, whose fragile habitat is being wrested from the non-native rainbow and brown trout by active fisheries management. Low elevation, slower and warmer streams have the greatest aquatic diversity including four reintroduced federally threatened and endangered small fish: the Smoky Madtom, Yellowfin Madtom, Spotfin Chub, and Duskytail Darter. Great Smoky Mountains National Park contains some of the largest tracts of wilderness in the East and is a critical sanctuary for a wide variety of animals. Protected in the park are some 65 species of mammals, over 200 varieties of birds, 67 native fish species, and more than 80 types of reptiles and amphibians.