THE FREMONT COUNTY LAND BRIEF
Land in the
Yellowstone Plateau setting.
Fremont County has 1,864 square miles of land in Idaho. 8 mapped landscape regions meet across Fremont County: Yellowstone Plateau, Eastern Snake River Basalt Plains, Dissected Plateaus and Teton Basin, among others.
Forested mountain ranges rise above grassy or shrubby intermountain valleys. The Middle Rockies combine alpine high country, partly wooded foothills and valleys supplied by mountain streams.
Regional context: Middle Rockies ↗ · Regional mapping across the county footprint
Where the landscape changes
Fremont County intersects 8 mapped regional units. The largest mapped shares are:
- Yellowstone Plateau44.7%
- Eastern Snake River Basalt Plains28.2%
- Dissected Plateaus and Teton Basin13.7%
- Barren Mountains6.1%
- Upper Snake River Plain5.6%
Snake River Plain in Fremont 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 Fremont County
The atlas lists 8 cities, towns, townships, and Census communities associated with Fremont County, including Island Park, St. Anthony, Teton. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Fremont County by land and water
The Census records 32.2 square miles of water within Fremont County, or 1.7% of its total area. That share is close to Fremont County’s 1.7%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Fremont County has 2,921.6 times the land area of nearby Ashton city (0.64 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Clark County, Jefferson County, Madison County, Teton County within Idaho. A tract near one of these lines should be matched to the county identifier on its own records.

