[7] The Blue Ridge Parkway runs 469 miles (755 km) along crests of the southern Appalachians and links two national parks: Shenandoah and Great Smoky Mountains.

Most of the rocks that form the Blue Ridge Mountains are ancient granitic charnockites, metamorphosed volcanic formations, and sedimentary limestone.

Recent studies completed by Richard Tollo, a professor and geologist at George Washington University, provide greater insight into the petrologic and geochronologic history of the Blue Ridge basement suites.

Modern studies have found that the basement geology of the Blue Ridge is made of compositionally unique gneisses and granitoids, including orthopyroxene-bearing charnockites.

Analysis of zircon minerals in the granite completed by John Aleinikoff at the U.S. Geological Survey has provided more detailed emplacement ages.

The lack of a calc-alkaline affinity and zircon ages less than 1.2 billion years old suggest that the Blue Ridge is distinct from the Adirondacks, Green Mountains, and possibly the New York–New Jersey Highlands.

The petrologic and geochronologic data suggest that the Blue Ridge basement is a composite orogenic crust that was emplaced during several episodes from a crustal magma source.

At the time of their emergence, the Blue Ridge were among the highest mountains in the world and reached heights comparable to the much younger Alps.

Statistical modelling predicts that the alpine tree line would exist at above 7,985 feet (2434 m) in the climate zone and latitude of the southern Appalachians.