THE FAIRFAX COUNTY LAND BRIEF
Land in the
Northern Inner Piedmont setting.
Fairfax County has 391 square miles of land in Virginia. 5 mapped landscape regions meet across Fairfax County: Northern Inner Piedmont, Piedmont Uplands, Chesapeake Rolling Coastal Plain, among others.
The Piedmont is a belt of irregular plains and hills between the Appalachians and the coastal plain. A complex mixture of older rocks underlies its pine and hardwood woodland landscapes.
Regional context: Piedmont ↗ · Regional mapping across the county footprint
Where the landscape changes
Fairfax County intersects 5 mapped regional units. The largest mapped shares are:
- Northern Inner Piedmont41.4%
- Piedmont Uplands22.3%
- Chesapeake Rolling Coastal Plain19%
- Triassic Lowlands12%
- Trap Rock and Conglomerate Uplands5.3%
Northern Piedmont in Fairfax County
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.
Read the regional source ↗Southeastern Plains in Fairfax County
Irregular plains of sand, silt and clay support a mix of pine and hardwood landscapes. The region has more relief than the lower coastal plain, with generally gentle stream gradients.
Read the regional source ↗Finding your parcel within Fairfax County
The atlas lists 69 cities, towns, townships, and Census communities associated with Fairfax County, including Great Falls, McLean, Reston. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Fairfax County by land and water
The Census records 15.5 square miles of water within Fairfax County, or 3.8% of its total area. That share is close to Fairfax County’s 3.8%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Fairfax County has 158.2 times the land area of nearby Long Branch CDP (2.47 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Alexandria city, Arlington County, Fairfax city, Falls Church city, Loudoun County, Prince William County within Virginia. A tract near one of these lines should be matched to the county identifier on its own records.

