Overview of Idaho Counties
Idaho has 44 counties organized across more than 83,000 square miles, ranging from dense mountain valleys to high desert plateaus. This guide explains how counties are ordered, compares them by population and area, and provides practical details for research, planning, and civic engagement. Whether you need alphabetical clarity or demographic context, this overview delivers verified, long-term reference information.
How Counties Are Ordered in Idaho
Alphabetical Order
Idaho counties in alphabetical order provide a consistent, easy-to-reference sequence for directories, indexes, and lookups. This arrangement removes population or geography bias and supports standardized reporting. Common use cases include legislative records, school district materials, and archival indexes.
- Ada County
- Adams County
- Bear Lake County
- Benewah County
- Bingham County
- Blaine County
- Boise County
- Bonner County
- Bonneville County
- Boundary County
- Butte County
- Camas County
- Caribou County
- Cassia County
- Clark County
- Clearwater County
- Custer County
- Elmore County
- Franklin County
- Fremont County
- Gem County
- Gooding County
- Idaho County
- Jefferson County
- Jerome County
- Kootenai County
- Latah County
- Lemhi County
- Lewis County
- Lincoln County
- Madison County
- Minidoka County
- Nez Perce County
- Oneida County
- Owyhee County
- Payette County
- Power County
- Shoshone County
- Teton County
- Twin Falls County
- Valley County
- Washington County
Population Order
Listing Idaho counties by population highlights where most residents live and informs resource allocation, service planning, and market analysis. The U.S. Census Bureau’s most recent official estimates anchor this view, emphasizing that rankings can shift with new estimates. For stable planning, consider multi-year averages and trends rather than single-year fluctuations.
Key County Facts at a Glance
Quick-reference table summarizing population, land area, and county seat for the ten most populous Idaho counties based on the latest official estimates.
| County | Population (Estimate) | Land Area (sq mi) | County Seat | Primary Urban Center |
|---|---|---|---|---|
| Ada | 529,000 | 1,053 | Boise | Boise Metro |
| Teton | 122,000 | 449 | Driggs | Jackson Hole Area |
| Kootenai | 171,000 | 1,247 | Coeur d’Alene | Coeur d’Alene Metro |
| Bonneville | 130,000 | 1,874 | Idaho Falls | Idaho Falls Metro |
| Washington | 113,000 | 902 | Weiser | Small Urban |
| Elmore | 28,000 | 3,097 | Mountain Home | Small Urban |
| Canyon | 74,000 | 594 | Caldwell | Boise Suburb |
| Gem | 20,000 | 560 | Emmett | Small Urban |
| Bingham | 52,000 | 2,120 | Blackfoot | Agricultural |
| Bannock | 67,000 | 1,100 | Pocatello | Pocatello Metro |
Alphabetical Listing and Quick Identifiers
Having a reliable alphabetical list supports lookup efficiency and reduces ambiguity when working with permits, addresses, or regulatory filings. Below is a concise enumeration of all 44 Idaho counties in strict alphabetical order, paired with county seats where concise accuracy is maintained.
- Ada County — Seat: Boise
- Adams County — Seat: Council
- Bear Lake County — Seat: Paris
- Benewah County — Seat: St. Maries
- Bingham County — Seat: Blackfoot
- Blaine County — Seat: Hailey
- Boise County — Seat: Idaho City
- Bonner County — Seat: Sandpoint
- Bonneville County — Seat: Idaho Falls
- Boundary County — Seat: Bonners Ferry
- Butte County — Seat: Arco
- Camas County — Seat: Fairfield
- Caribou County — Seat: Soda Springs
- Cassia County — Seat: Burley
- Clark County — Seat: Dubois
- Clearwater County — Seat: Orofino
- Custer County — Seat: Challis
- Elmore County — Seat: Mountain Home
- Fremont County — Seat: St. Anthony
- Gem County — Seat: Emmett
- Gooding County — Seat: Gooding
- Idaho County — Seat: Grangeville
- Jefferson County — Seat: Rigby
- Jerome County — Seat: Jerome
- Kootenai County — Seat: Coeur d’Alene
- Latah County — Seat: Moscow
- Lemhi County — Seat: Salmon
- Lewis County — Seat: Nezperce
- Lincoln County — Seat: Shoshone
- Madison County — Seat: Rexburg
- Minidoka County — Seat: Rupert
- Nez Perce County — Seat: Lewiston
- Oneida County — Seat: Malad City
- Owyhee County — Seat: Murphy
- Payette County — Seat: Payette
- Power County — Seat: American Falls
- Shoshone County — Seat: Kellogg
- Teton County — Seat: Driggs
- Twin Falls County — Seat: Twin Falls
- Valley County — Seat: Cascade
- Washington County — Seat: Weiser
Population and Area Comparison
Understanding both population and land area helps contextualize urban density, rural character, and planning priorities. The table below pairs estimated population with land area for the ten most populous counties, illustrating differences in scale and concentration.
Context and Practical Uses
Knowing how Idaho counties are ordered and their basic attributes supports accurate research, compliance, and communication. Alphabetical order is reliable for directories and legal indexes, while population-based ordering aids demographic analysis and service planning. County area and seat information further clarify jurisdiction and access to administrative services.
Additional Notes on Data and Updates
Population figures are drawn from the most recent U.S. Census Bureau estimates and represent the best available point-in-time data. Geographical area is based on U.S. Census Bureau gazetteer files. These bases are stable and suitable for evergreen reference. When exact current numbers matter for time-sensitive decisions, consult the official U.S. Census Bureau or Idaho state portals for the latest revisions.