THE BOISE COUNTY LAND BRIEF
Land in the
Southern Forested Mountains setting.
Boise County has 1,899.4 square miles of land in Idaho. 5 mapped landscape regions meet across Boise County: Southern Forested Mountains, Foothill Shrublands-Grasslands, Hot Dry Canyons, among others.
A deeply cut mountainous plateau forms the Idaho Batholith. Granitic terrain supports conifer forests, while deep canyons introduce warmer settings with pine, shrubs and grasses.
Regional context: Idaho Batholith ↗ · Regional mapping across the county footprint
Where the landscape changes
Boise County intersects 5 mapped regional units. The largest mapped shares are:
- Southern Forested Mountains77.2%
- Foothill Shrublands-Grasslands9.7%
- Hot Dry Canyons9.4%
- High Idaho Batholith3.2%
- Semiarid Foothills0.5%
Snake River Plain in Boise County
The Snake River Plain is lower and gentler than its surrounding mountains. Alluvial valleys, sagebrush-covered plains, low hills and scattered lava fields form its principal landscape patterns.
Read the regional source ↗Finding your parcel within Boise County
The atlas lists 8 cities, towns, townships, and Census communities associated with Boise County, including Robie Creek, Garden Valley, Banks. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Boise County by land and water
The Census records 7.38 square miles of water within Boise County, or 0.4% of its total area. That share is close to Boise County’s 0.4%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Boise County has 936.6 times the land area of nearby Lowman CDP (2.03 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Ada County, Custer County, Elmore County, Gem County, Valley County within Idaho. A tract near one of these lines should be matched to the county identifier on its own records.

