Ridge line
A ridge line is the narrow, elongated crest along the top of a hill or mountain. In Virginia's mountain ridge statute the crest is the uppermost line from which land falls away on at least two sides, and a ridge includes all land within 100 feet below the elevation of any portion of that line.
The mapmaker's ridge beside the statute's ridge
To the U.S. Geological Survey, a ridge is an elevation with a narrow, elongated crest that can be part of a hill or a mountain. To Va. Code 15.2-2295.1, a ridge is the crest line plus all the land within 100 feet below the elevation of any part of that line.
The first meaning names a landform. It is how a map labels a feature, and it draws no boundary around it. The second meaning exists for one purpose: to mark out the ground a Virginia locality may choose to regulate for tall buildings. The statute builds its definition in steps, starting from the crest, which it defines as the uppermost line of a mountain or chain of mountains from which the land falls away on at least two sides to a lower elevation.
| Question | USGS feature class | Va. Code 15.2-2295.1 |
|---|---|---|
| What the word names | An elevation with a narrow, elongated crest, part of a hill or mountain | The crest line and all land within 100 feet below the elevation of any portion of it |
| How far down it reaches | Not part of the definition | 100 feet, measured vertically below the crest line's elevation |
| Height test | None in the definition | A protected mountain ridge has an elevation of 2,000 feet or more and stands 500 feet or more above an adjacent valley floor |
| What it is for | Naming and classifying a geographic feature | Letting a locality regulate the height and location of tall buildings on protected ridges |
What the definition is used for: tall buildings, measured by the locality
The statute is not itself a ban on building on a ridge. It gives a locality that has a protected mountain ridge the option of regulating tall buildings on it.
The statute's tall building or structure has a vertical height of more than 40 feet, as determined by ordinance, measured from the natural finished grade of the crest or of the high side of the slope of a ridge. Towers and transmission equipment, slender structures and minor projections such as chimneys and flagpoles, and designated historic landmarks are excluded.
What an ordinance must contain, and whether a home can be put on top of a ridge at all, are taken up in whether you can build on a ridge top.
Carroll County's ridges, and the office that knows the local rule
Carroll County's 2024 comprehensive plan places a small part of the county's northwestern corner in the Ridge and Valley Province, whose ridges run roughly northeast to southwest, and says the Eastern Continental Divide runs through the county roughly along the Blue Ridge Parkway.
Whether a ridge in a given county is a protected mountain ridge in the statute's sense, and whether that county has adopted an ordinance under it, are local questions. The statute makes the ordinance optional, so the answer is in the county's own code and its planning office. For Carroll County that is Carroll County Land Use and Planning, 605-1 Pine Street, Hillsville, 276-730-3008.
Grayson County shows how the question can surface on paper. Its zoning permit form carries a Mountain Ridge Construction Information section that asks for the project's elevation above sea level and the building height from adjacent grade. The ordinance rule behind those questions sits with Grayson County Planning and Community Development.
A ridge line also matters for what can be seen from it and what can see it, which is a different idea with its own entry: what a viewshed is. How a ridge, the slopes below it and the siting of a house, a drive and a septic site fit together is laid out in slope, aspect and building on a mountain tract.
Own a parcel that runs up to a ridge line?
Send the county, the road and the acreage, and Lowell will pull what is recorded on the tract and name the county office that answers the ridge question. No cost, no obligation.
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Questions about this term
Does a ridge labeled on a map fall under the ridge statute?
Not on the label alone. The U.S. Geological Survey's Ridge is a landform class: an elevation with a narrow, elongated crest. Va. Code 15.2-2295.1 applies its own tests, and a protected mountain ridge has an elevation of 2,000 feet or more and stands 500 feet or more above an adjacent valley floor. The governing body's determinations of heights and elevations are conclusive, and the height rules reach a ridge only where a locality has adopted an ordinance under the section.
Where is a tall building's height measured from under the ridge statute?
The statute measures a tall building or structure from the top of the natural finished grade of the crest, or the natural finished grade of the high side of the slope of a ridge, to the building's uppermost point, and the threshold is more than 40 feet as determined by ordinance. The locality's ordinance and its planning office settle the number on a real project.
Where this page's facts come from
Every rule, office and figure above traces to one of these. Rules change; check the office before you act on one.
- GNIS domestic names feature classes (Ridge) U.S. Geological Survey
- Va. Code 15.2-2295.1: regulation of tall buildings or structures on protected mountain ridges Virginia General Assembly
- 2024 Comprehensive Plan (Ridge and Valley Province, Eastern Continental Divide) Carroll County, Virginia
- Land Use and Planning Carroll County, Virginia
- Zoning Permit Form 0100, revised 2024-10-25 (Mountain Ridge Construction Information) Grayson County, Virginia