THE MONTGOMERY COUNTY LAND BRIEF
Land in the
Piedmont Uplands setting.
Montgomery County has 493.1 square miles of land in Maryland. 3 mapped landscape regions meet across Montgomery County: Piedmont Uplands, Triassic Lowlands, Chesapeake Rolling Coastal Plain.
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
Montgomery County intersects 3 mapped regional units. The largest mapped shares are:
- Piedmont Uplands83.3%
- Triassic Lowlands15%
- Chesapeake Rolling Coastal Plain1.7%
Southeastern Plains in Montgomery 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 Montgomery County
The atlas lists 59 cities, towns, townships, and Census communities associated with Montgomery County, including Potomac, Germantown, Darnestown. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Montgomery County by land and water
The Census records 13.8 square miles of water within Montgomery County, or 2.7% of its total area. That share is close to Montgomery County’s 2.7%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Montgomery County has 47.7 times the land area of nearby Gaithersburg city (10.3 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Frederick County, Howard County, Prince George's County within Maryland. A tract near one of these lines should be matched to the county identifier on its own records.

