Stone Mountain is the centerpiece of Stone Mountain State Park

Stone Mountain State Park

Stone Mountain State Park is a North Carolina state park in Alleghany and Wilkes Counties, North Carolina in the United States.-Size and location:Located in Wilkes and Alleghany counties of North Carolina, it covers 13,747 acres ....

. It is a dome of exposed granite

Granite

Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

 (specifically a quartz diorite

Diorite

Diorite is a grey to dark grey intermediate intrusive igneous rock composed principally of plagioclase feldspar , biotite, hornblende, and/or pyroxene. It may contain small amounts of quartz, microcline and olivine. Zircon, apatite, sphene, magnetite, ilmenite and sulfides occur as accessory...

 to granodiorite

Granodiorite

Granodiorite is an intrusive igneous rock similar to granite, but containing more plagioclase than orthoclase-type feldspar. Officially, it is defined as a phaneritic igneous rock with greater than 20% quartz by volume where at least 65% of the feldspar is plagioclase. It usually contains abundant...

) of Devonian

Devonian

The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...

 age, which has intruded into the gneiss of the Precambrian

Precambrian

The Precambrian is the name which describes the large span of time in Earth's history before the current Phanerozoic Eon, and is a Supereon divided into several eons of the geologic time scale...

 Alligator Back Formation. It rises sharply over 600 feet (183 m) above the surrounding terrain. The mountain, which has an elevation of 2,305 feet (706 m) above sea level, is known for its barren sides and distinctive brown-gray color, and can be seen for miles. The mountain offers some of the best rock climbing

Rock climbing

Rock climbing also lightly called 'The Gravity Game', is a sport in which participants climb up, down or across natural rock formations or artificial rock walls. The goal is to reach the summit of a formation or the endpoint of a pre-defined route without falling...

 in North Carolina, and the park's creeks and streams feature excellent brook trout

Brook trout

The brook trout, Salvelinus fontinalis, is a species of fish in the salmon family of order Salmoniformes. In many parts of its range, it is known as the speckled trout or squaretail. A potamodromous population in Lake Superior are known as coaster trout or, simply, as coasters...

 fishing.

Because the mountain is the best example of a monadnock

Monadnock

A monadnock or inselberg is an isolated rock hill, knob, ridge, or small mountain that rises abruptly from a gently sloping or virtually level surrounding plain...

 in massive granite in North Carolina it was designated a National Natural Landmark

National Natural Landmark

The National Natural Landmark program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only natural areas program of national scope that identifies and recognizes the best examples of biological and geological features in...

in May 1974.