THE LEWIS AND CLARK COUNTY LAND BRIEF
Land in the
Southern Carbonate Front setting.
Lewis and Clark County has 3,458.4 square miles of land in Montana. 13 mapped landscape regions meet across Lewis and Clark County: Southern Carbonate Front, Foothill Grassland, Eastern Divide Mountains, among others.
High mountain ranges extend south from Canada into northwestern Montana. Glacial terrain, conifer forests and alpine country are central features, with more ice-covered highlands than the Northern Rockies.
Regional context: Canadian Rockies ↗ · Regional mapping across the county footprint
Where the landscape changes
Lewis and Clark County intersects 13 mapped regional units. The largest mapped shares are:
- Southern Carbonate Front18%
- Foothill Grassland16.9%
- Eastern Divide Mountains16.6%
- Rattlesnake-Blackfoot-South Swan-Northern Garnet-Sapphire Mountains16.4%
- Townsend Basin10.4%
Northwestern Glaciated Plains in Lewis and Clark County
Glaciated plains bridge the wetter eastern prairie and the drier, more broken Great Plains. Numerous prairie potholes and other seasonal or persistent wetlands are characteristic regional landforms.
Read the regional source ↗Middle Rockies in Lewis and Clark County
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.
Read the regional source ↗Finding your parcel within Lewis and Clark County
The atlas lists 18 cities, towns, townships, and Census communities associated with Lewis and Clark County, including Helena Valley Northeast, Helena Valley West Central, Helena Valley Southeast. The list includes overlapping geography types and does not divide the county into exclusive service areas.
Lewis and Clark County by land and water
The Census records 39.2 square miles of water within Lewis and Clark County, or 1.1% of its total area. That share is close to Lewis and Clark County’s 1.1%. This is geographic context; waterfront status and usable land must be checked at the parcel.
For scale, Lewis and Clark County has 7,789.1 times the land area of nearby Milford Colony CDP (0.44 square miles). These areas describe boundaries, not comparable property prices.
The Census boundary meets Broadwater County, Cascade County, Flathead County, Jefferson County, Meagher County, Powell County, Teton County within Montana. A tract near one of these lines should be matched to the county identifier on its own records.

