THE LOUDOUN COUNTY LAND BRIEF
Land in the
Piedmont Uplands setting.
Loudoun County has 515.7 square miles of land in Virginia. 6 mapped landscape regions meet across Loudoun County: Piedmont Uplands, Triassic Lowlands, Trap Rock and Conglomerate Uplands, among others.
Rounded low hills, open valleys and irregular plains form a transition between Appalachian highlands and the coastal plain. The underlying geology mixes metamorphic, igneous and sedimentary rocks.
Regional context: Northern Piedmont ↗ · Regional mapping across the county footprint
Where the landscape changes
Loudoun County intersects 6 mapped regional units. The largest mapped shares are:
- Piedmont Uplands51.8%
- Triassic Lowlands26.3%
- Trap Rock and Conglomerate Uplands11.4%
- Northern Igneous Ridges6.1%
- Northern Sedimentary and Metasedimentary Ridges3.8%
Blue Ridge in Loudoun County
Forested ridges, plateaus and high mountains extend through the Blue Ridge. Elevation, rainfall and sheltered coves create marked differences in forest communities across short distances.
Read the regional source ↗Finding your parcel within Loudoun County
The atlas lists 31 cities, towns, townships, and Census communities associated with Loudoun County, including Ashburn, Leesburg, South Riding. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Loudoun County by land and water
The Census records 5.59 square miles of water within Loudoun County, or 1.1% of its total area. That share is close to Loudoun County’s 1.1%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Loudoun County has 2,323.2 times the land area of nearby Hamilton town (0.22 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Clarke County, Fairfax County, Fauquier County, Prince William County within Virginia. A tract near one of these lines should be matched to the county identifier on its own records.

