the Spanish discovered the Appalachee near modern Tallahassee, Forida, and the name of the group of Native Americans was applied to the mountains to the north
Source: David Rumsey Historical Map Collection, Carolina And Georgia (by Emanuel Bowen and John Gibson, 1758)
The "mountains" of Virginia start at the Blue Ridge, but defining the Appalachians vs. the Blue Ridge vs. the Alleghenies is a judgment call. The cultural terms for the Appalachians mountains does not always match the geological distinctions.
The "Valley and Ridge Province" extends between the Blue Ridge and the Allegheny Front, and stops at the edge of the Appalachian Plateau. If a person lumps the Blue Ridge in with the mountains of West Virginia and Kentucky, then Floyd County, Mount Rogers, and Galax are part of the Appalachians - but should the New River Valley and Bristol be included? If a person splits out the various provinces so only the Appalachian Plateau west of the Allegheny Front qualify as "Appalachia," then what is the appropriate label for the cultural patterns of the Blue Ridge (including mountain music and moonshine)?
Where you grow up might makes a difference. People who grow up in the Shenandoah Valley or the New River Valley don't always assume the mountains are to the west. Residents of Blacksburg or Roanoke may refer to specific mountains - Tinker Mountain, Brush Mountain, etc. - rather than say "I'm going mountain biking in the Blue Ridge on Saturday."
Virginian who grow up near the Fall Line or in Tidewater, are more likely to be "lumpers" who call all those bumps to the west the Appalachians. In contrast, those who grow up west of Route 15 are probably "splitters" who distinguish the Blue Ridge from the Appalachian Plateau, and consider the Shenandoah and other valleys in-between to be a unique region. Alleghany County could be considered part of the Allegheny Mountains, even though there spelling is not consistent - and much of the county is, geologically, in the Valley and Ridge physiographic province.
Virginia topography and geology defines physiographic provinces, but people can define regional boundaries by cultural as well as physical patterns
Source: National Oceanographic and Atmospheric Administration (NOAA), The Global Land One-kilometer Base Elevation (GLOBE), Project Conterminous 48 USA states
bedrock deformed by the collision of the North America and Africa tectonic plates roughly 300 million years ago has been shaped by erosion since then, and now form a range of mountains stretching from Georgia to the Maritime provinces of Canada
Source: National Oceanic and Atmospheric Administration, GLOBE: A Gallery of High Resolution Images
the name of a Native American group in Florida was applied to the mountain range stretching towards the north
Source: J. Carter Brown Library, Carolina (by Herman Moll, c.1763)
from a geological perspective, the Appalachians extend north into Canada and south into Alabama
Source: US Geological Survey (USGS) and Geologic Society of America (GSA), Geologic Map of North America - South
From a geologic perspective the Blue Ridge, the Valley and Ridge province, and the Appalachian Plateau are distinctly different.
The one billion year old core of the Blue Ridge was created during the Grenville orogeny, perhaps when the supercontinent Rodinia formed. The Blue Ridge core rocks are igneous rocks, with a coating of younger volcanic lava that was later metamorphosed. The Blue Ridge's core bedrock was created during a mountain-building episode when tectonic plates collided.
In contrast, just to the west in the Shenandoah Valley are sedimentary layers that are only half the age of the Blue Ridge granite and grandiorite. The limestones in the Valley and Ridge physiographic province are "only" 500 million years old, dating from the Cambrian Period or even later. The oldest of those sedimentary layers were deposited in a peaceful ocean environment at the edge of a continental plate, comparable to the setting of the Bahamas today.
Further west, the rocks in the Appalachian Plateau are also less than half the age of the core of the Blue Ridge, and most sedimentary layers in the Appalachian Plateau are younger than the rocks exposed in the Valley and Ridge. The layers in the Appalachian Plateau are also flat. The energy of the collision between Africa-North America roughly 300 million years ago tilted and twisted the sedimentary layers in the Valley and Ridge province, but further west the layers were not crumpled by the energy is the tectonic collisions. Erosion has stripped away more of the layers in the Valley and Ridge province, while younger rocks remain in the Appalachian Plateau.
One other distinction between the Blue Ridge and the Appalachian Plateau: the Blue Ridge has been pushed westwards perhaps 40 miles by the collision with Africa. It appears to have broken free from its original roots to the Grenville-age basement, and been shoved west on top of the younger rocks exposed now in the Shenandoah and New River valleys. The rocks of the Appalachian Plateau have drifted with the rest of the continental plate, but have not been shoved from their original site of deposition.
the limestone formations in the Valley and Ridge province were deposited on the edge of the tectonic plate before the collision with Africa
Source: Ron Blakely, Paleogeography and Geologic Evolution of North America - Late Cambrian (500Ma)
From a cultural perspective, the "mountain people" of the Appalachians often include the isolated homesteads in the Blue Ridge as well as the Appalachian Plateau.
After the Civil War, Northern social workers realized that poverty was common in the mountains of Virginia. Educational levels were low, some religious rituals bordered on mysticism, and disputes were settled by extra-legal processes rather than standard law-and-order techniques.
Hillsides provided thin soils in contrast to valley bottomlands or even the Piedmont, and poor roads made it very difficult to transport crops or products to market. The standard solution for compressing the volume of sorghum, corn, barley, and wheat was to distil the grains into alcohol, which created a high-value product that was far easier to load on a mule.
To generate donations to support various initiatives, the concept of Appalachia as a blighted, isolated region was popularized. That helped generate funds from donors, but the stigma of "poor Appalachian" became unpopular in the region.
In the 1960's, President Kennedy and the President Johnson sought to relieve poverty in the area, setting up the Appalachian Regional Commission to funnel grants for various social programs. The counties in the Shenandoah and Roanoke valleys had the opportunity to be included in the designated area for extra grant funding, but some declined. Being associated with "Appalachia" could be a deterrent, limiting the interest of private sector businesses to locate in the counties.
The jurisdiction most famous for moonshining in Virginia, Franklin County, ended up being excluded from the boundaries. In the end, the following counties were included:
none of the northern Blue Ridge counties in Virginia north and east of Rockbridge ended up within the Appalachian Regional Commission boundaries
Source: Appalachian Regional Commission, The Appalachian Region
the rural character of the Appalachians is revealed in a satellite image of night lights in urban areas - and where they are absent
Source: National Oceanic and Atmospheric Administration (NOAA), GLOBE: A Gallery of High Resolution Images, Conterminous 48 USA states (with lights)