Great Smoky Mountains National Park covers 2,114 km² (816 sq mi) of the southern Appalachians, split roughly evenly between Tennessee and North Carolina along a state line that follows the main ridge. With more than 11 million visitors in 2025 it is the most visited national park in the United States, and it is also the most biologically diverse: about 19,000 species have been documented there, and scientists estimate that 80,000 to 100,000 more may be present. Elevations run from about 267 m (875 ft) to 2,025 m (6,643 ft) on Kuwohi, formerly Clingmans Dome, the highest point in Tennessee. Congress chartered the park in 1934, Franklin D. Roosevelt dedicated it in 1940, and UNESCO listed it as a World Heritage Site in 1983. Nearly every species here belongs to a particular height, valley or stream, and the sections below take them group by group.
Salamanders of the Smokies: Up to 31 Species and the Red-Cheeked Salamander
The park calls itself the "Salamander Capital of the World", and the numbers support it. Five of the world's nine salamander families live in the range, with up to 31 species between them. The wet climate suits them: humid air forced up the slopes brings 1,300 to 2,000 mm (50 to 80 in) of precipitation a year, and the park holds an estimated 4,700 km (2,900 mi) of streams, all within the Tennessee River watershed.
The emblem of this group is the red-cheeked salamander, Plethodon jordani, a steel-grey animal with red or orange patches on the side of its head. Its main populations lie along the Tennessee–North Carolina border in the Smokies, with only small separate populations in Rabun County, Georgia. Its recorded altitude range is 210 to 1,950 m, and almost all of that range lies inside the park boundary. It is a terrestrial species that shelters under rocks and rotten logs by day and forages at night or in rain, and it needs very little room: studies put the home range at about 11 m² for a male and 2.8 m² for a female. Salamanders displaced 300 m or more mostly found their way home.
Close relatives fill out the list. The imitator salamander, which mimics the red-cheeked species, lives only in the Smokies and the neighbouring Plott Balsams and Great Balsam Mountains. The southern gray-cheeked salamander and southern Appalachian salamander are confined to the wider region. In the fast streams lives the hellbender, which can reach 74 cm (29 in). The park also counts 14 species of frogs and toads, including the spring peeper and wood frog, bringing its amphibian total to 43 species. Reptiles add 40 more, among them the timber rattlesnake, found at all elevations, and the copperhead, mostly in the lower valleys.
American Black Bears: About 1,900 Across 2,114 Square Kilometres
The park's best-known mammal is the American black bear. An estimated 1,900 live in the park, the densest black bear population east of the Mississippi River, which works out at close to one bear per square kilometre. Most adults weigh between 45 and 140 kg (100 to 300 lb), though bears of up to 270 kg (600 lb) have been documented. The park gave them back a large, connected block of forest: the reserve adjoins the Cherokee National Forest in Tennessee and the Nantahala National Forest in North Carolina, so forest habitat continues well beyond the boundary.
Bears are only one of 65 mammal species. The park has 27 rodent species, including the endangered northern flying squirrel, and 12 bat species, among them the endangered Indiana bat and Rafinesque's big-eared bat. The bobcat is the only wild cat that remains; cougars once lived here and unconfirmed sightings are still reported. White-tailed deer multiplied after the park was created, and coyotes arrived on their own in recent decades.
Cove Hardwoods and Albright Grove: More Than 130 Tree Species Below 1,400 Metres
Forest covers about 95 percent of the park, and an estimated 20 to 25 percent of it is old growth, one of the largest blocks of old-growth temperate deciduous forest in North America. Botanists divide it into three zones by height, and the lowest is the richest. Cove hardwood forest fills the sheltered valleys and lower slopes below about 1,400 m (4,500 ft), in deep, moist soil. More than 130 tree species grow in its canopy, including tulip tree, yellow buckeye, basswood, sugar maple, silverbell, cucumber magnolia and eastern hemlock. Around 290 km² (72,000 acres) of it has never been logged. Albright Grove, on the Maddron Bald Trail between Gatlinburg and Cosby, is an easily reached stand, with some of the oldest and tallest trees in the range.
The understorey adds redbud, flowering dogwood, mountain laurel and Catawba rhododendron. In all, the park holds more than 1,500 species of flowering plants, more than any other national park in North America, including 35 orchids and 27 violets, alongside 101 species of native trees. One tree is missing: the American chestnut, once the most valued tree of the mountain farms, was killed by the introduced chestnut blight in the first half of the 20th century.
The cove streams belong to the brook trout, the only trout native to the range. Rainbow and brown trout were introduced in the first half of the 20th century and outcompete it in warmer water, so most brook trout now live in streams above about 910 m (3,000 ft), where temperatures usually stay below 16 °C (61 °F). About 1,727 km of the park's streams support fish, and four protected species live in them: the smoky madtom, yellowfin madtom, spotfin chub and duskytail darter.
Spruce-Fir on Kuwohi and Mount Guyot: An Ice-Age Relict Above 1,700 Metres
Climbing from the coves is often compared to driving from Tennessee to Canada. Above the cove forest comes northern hardwood forest of yellow birch and American beech, the highest broad-leaved forest in the eastern United States, with about 116 km² (28,600 acres) of old growth. Its oddity is the beech gap, a high pass taken over by wind-twisted beech trees, from which red spruce is excluded for reasons nobody has explained.
Higher still, usually above 1,700 m (5,500 ft), lies the Southern Appalachian spruce-fir forest, a relict of the last glacial period. About 20,000 years ago the ice sheets never reached the Smokies, but tundra covered the summits and spruce-fir grew in the valleys. When the climate warmed between about 12,500 and 6,000 years ago, hardwoods returned and the conifers retreated to the peaks, where they survive on Kuwohi, Mount Guyot (2,018 m) and Mount Le Conte (2,010 m). About 43 km² (10,600 acres) of it is old growth, and some red spruces are thought to be 300 years old.
This forest has been reshaped within living memory. Fraser fir, which grows only in the southern Appalachians, once dominated the ground above about 1,900 m (6,200 ft). The balsam woolly adelgid, an introduced insect, reached the Smokies in the early 1960s and killed roughly 90 percent of the mature firs, which is why dead grey trunks still stand on Kuwohi and Old Black. Young firs have since regenerated on Mount Collins and Kuwohi. The red-cheeked salamander is plentiful here, as are northern birds such as the winter wren, dark-eyed junco and Canada warbler. Of the nearly 120 bird species that breed in the park, 52 winter in the neotropics.
Synchronous Fireflies at Elkmont Every June
More than 9,000 insect species have been recorded in the park, and one draws crowds. Photinus carolinus, the Smokies synchronous firefly, puts on its mating display over about two weeks between late May and mid-June, with its population centre near Elkmont, Tennessee, a historic district in the park's Tennessee half. It was the first North American firefly found to flash in synchrony. A male typically gives four to eight bright flashes over two to four seconds, then stays dark for eight to 12 seconds; thousands doing it together make waves of light pass through the woods. Scientists suggest the shared dark period lets males spot the fainter answering flashes of females.
The fireflies favour mature forest. In the southern part of their range they live in hardwood forests 65 years old or older, in river valleys at 430 to 1,830 m. Their larvae spend most of their lives below the soil surface, eating snails and worms.
Much of what is known about the park's smaller life comes from the All Taxa Biodiversity Inventory, an attempt to list every living species in the park. It was planned at a meeting of scientists in Gatlinburg in December 1997, and the non-profit Discover Life in America was set up in 1998 to run it. When it began, only about a tenth of the 99,000 species then estimated were known. The inventory has since added 7,391 species new to the park and 922 new to science. Among the totals the park now reports are about 2,700 fungi, 952 algae and 563 lichens.
Elk at Cataloochee, River Otters and the Red Wolf Trial of 1991
Several of the park's larger animals were brought back. North American river otters were reintroduced in phases between 1986 and 1994. Elk were released in 2001 and 2002 and are now most abundant in Cataloochee, a valley of old farm fields and preserved buildings in the park's south-east corner in North Carolina.
Not every attempt worked. Red wolves were released in 1991, but the experiment failed, and in 1998 the U.S. Fish and Wildlife Service removed them to Alligator River National Wildlife Refuge on the North Carolina coast. In the other direction, European wild boar, introduced as game animals in the early 20th century, have spread through the southern Appalachians. They root up and destroy plants and take food that bears would otherwise eat, so the park pays hunters to remove them and leaves the carcasses where bears can feed.
Those efforts follow a long shift in how the land is used. Before 1934 much of it was farmed or logged, with red spruce on the high ridges cut in the 1910s. Since then, recovering forest has let bears, salamanders and brook trout reclaim their old range, while air quality has improved too: visibility on the haziest days rose from about 14 km (9 mi) in 1998 to about 64 km (40 mi) in 2018. The ranges and rivers that shelter this wildlife are covered in our guides to the Appalachian Mountains, Tennessee's geography and the geography of North Carolina.