The Blue Ridge Mountains are a physiographic province of the larger Appalachian Mountains range. The mountain range is located in the eastern United States, and extends 550 miles southwest from southern Pennsylvania through Maryland, West Virginia, Virginia, North Carolina, South Carolina, Tennessee, and Georgia. This province consists of northern and southern physiographic regions, which divide near the Roanoke River gap. To the west of the Blue Ridge, between it and the bulk of the Appalachians, lies the Great Appalachian Valley, bordered on the west by the Ridge and Valley province of the Appalachian range.
The Blue Ridge Mountains are known for having a bluish color when seen from a distance. Trees put the "blue" in Blue Ridge, from the isoprene released into the atmosphere. This contributes to the characteristic haze on the mountains and their perceived color.
Within the Blue Ridge province are two major national parks – the Shenandoah National Park in the northern section, and the Great Smoky Mountains National Park in the southern section. The eight national forests include George Washington and Jefferson, Cherokee, Pisgah, Nantahala and Chattahoochee. The Blue Ridge Parkway, a 469-mile (755 km) long scenic highway, connects the two parks and runs along the ridge crest-lines, as does the Appalachian Trail.
The forest environment provides natural habitat for many plants, trees, and animals.
The Blue Ridge Mountains have stunted oak and oak-hickory forest habitats, which comprise most of the Appalachian slope forests. Flora also includes grass, shrubs, hemlock and mixed-oak pine forests.
While the Blue Ridge range includes the highest summits in the eastern United States, the climate is nevertheless too warm to support an alpine zone, and thus the range lacks the tree line found at lower elevations in the northern half of the Appalachian range. Statistical modelling predicts that the alpine treeline would exist at above 7,985 feet (2434 m) in the climate zone and latitude of the southern Appalachians. The highest parts of the Blue Ridge are generally vegetated in dense Southern Appalachian spruce-fir forests.