County outline
Where Bannock County is located
Area breakdown
Land accounts for 96.9% of Bannock County’s measured area and water for 3.1%. Its combined area converts to 2,973.4 square kilometers or approximately 734,746 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 1,112.489 | 2,881.333 | 711,993 |
| Water | 35.552 | 92.079 | 22,753.3 |
| Total | 1,148.041 | 2,973.413 | 734,746.2 |
How Bannock County compares
By original Census land area, Bannock County ranks #27 of 44 in Idaho and #567 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.846 times the Idaho county-equivalent median of 1,315.7 square miles. It accounts for 1.3% of the combined county land area in the state.
See the complete Idaho ranking · What counts as a county equivalent?
Population and density of Bannock County
The Census Bureau estimates that 91,591 people lived in Bannock County on July 1, 2025. That ranks #670 of 3,222 county equivalents nationally and #6 of 44 in Idaho. Since the April 1, 2020 estimates base of 87,023, the population has grown by 4,568 (+5.2%), compared with +10.4% for Idaho as a whole.
With 1,112.5 square miles of land, that is 82 people per square mile (32 per km²), placing Bannock County #1,130 nationally for density and #5 in Idaho. The median county equivalent has 47 people per square mile; the Idaho median is 10. Put another way, there are about 7.8 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 87,294 | 88,605 | 89,855 | 90,538 | 90,969 | 91,591 |
| Change | — | +1,311 | +1,250 | +683 | +431 | +622 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Bannock County
7 incorporated places lie at least partly in Bannock County. Together they are home to 78,603 people (85.8%); the other 12,988 (14.2%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Pocatello city, with 58,771 residents in the county (the city extends into 1 other county). Among places with at least 1,000 residents in 2020, Chubbuck city grew fastest since then (+7.9%).
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Pocatello cityCounty seat · Also in 1 other county | 58,771 | +3.6% | 34.9 |
| Chubbuck city | 16,823 | +7.9% | 7.079 |
| Inkom city | 862 | +7.8% | 0.956 |
| McCammon city | 828 | +0.2% | 2.228 |
| Downey city | 583 | +3.4% | 0.96 |
| Lava Hot Springs city | 374 | +4.2% | 0.698 |
| Arimo city | 362 | +2.3% | 0.496 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Bannock County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Bannock County is a central county of the Pocatello, ID Metropolitan Statistical Area. Bannock County is the area’s only county equivalent, so the metro area has the same 1,112.5 square miles of land. By combined land it ranks #269 of 393 metropolitan areas, and #377 by population.
ZIP codes
10 ZIP Code Tabulation Areas have land in Bannock County; 9 of them have most of their land inside the county, and the others mainly cover neighboring areas.
83201832028320483209832148323483245832468325083281
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Bannock County
Bannock County shares a land border with 5 county equivalents. It has more land than 1 of them. The largest neighbor is Bingham County (2,093.7 mi²) and the smallest is Franklin County (663.1 mi²). Together with its neighbors, Bannock County forms a block of 8,236.3 mi² of land, of which it holds 13.5%.
| Bordering county equivalent | Land mi² | Size vs. Bannock | Compare |
|---|---|---|---|
| Bingham County | 2,093.7 | 1.9× larger | Compare |
| Caribou County | 1,764.2 | 1.6× larger | Compare |
| Power County | 1,403.8 | 1.3× larger | Compare |
| Oneida County | 1,199 | 1.1× larger | Compare |
| Franklin County | 663.1 | 1.7× smaller | Compare |
How big is Bannock County compared with U.S. states?
Bannock County has more land than 1 of the 50 states. It is about 1.1 times the land area of Rhode Island (1,033.9 mi²), while Delaware, the next larger state, has 1.8 times as much land (1,948.6 mi²). Idaho’s county land could hold about 74 areas the size of Bannock County.
Another way to picture it: the same land area would fill a square about 33.4 miles (53.7 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Bannock County?
Bannock County has more land than 2,655 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Bannock County at #629 nationally by total area, 62 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.
Its water share is 3.1%, compared with a national county-equivalent median of 1.2% — 1.9 percentage points higher. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Bannock County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #566 | Oneida County, Wisconsin | 1,113.9 | Compare |
| #567 | Bannock County, Idaho | 1,112.5 | This county |
| #568 | Jefferson County, Alabama | 1,111.6 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 42.692921, -112.228982. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 2,881,334,331 m²; AWATER: 92,078,183 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Bannock County?
Bannock County, Idaho has 1,112.5 square miles (2,881.3 km²) of land and 35.6 square miles of water, for a total area of 1,148 square miles. It ranks #567 of 3,222 U.S. county equivalents by land area.
Is Bannock County the largest county in Idaho?
No. Bannock County ranks #27 of 44 in Idaho by land area. The largest is Idaho County, with 8,477.5 square miles of land.
What counties border Bannock County?
Bannock County shares a land border with Caribou County, Power County, Bingham County, Oneida County, and Franklin County.
What is the population of Bannock County?
The Census Bureau estimates Bannock County had 91,591 residents on July 1, 2025, ranking #670 of 3,222 county equivalents. That is 82 people per square mile of land.
What is the county seat of Bannock County?
The county seat of Bannock County is Pocatello.
What cities and towns are in Bannock County?
Bannock County has 7 incorporated places. The most populous five are Pocatello city, Chubbuck city, Inkom city, McCammon city, and Downey city; 12,988 residents live outside any incorporated place.
Is Bannock County part of a metropolitan area?
Yes. It is a central county of the Pocatello, ID Metropolitan Statistical Area.
How many ZIP codes are in Bannock County?
10 ZIP Code Tabulation Areas have land in Bannock County, and 9 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Bannock County compare with U.S. states?
It has more land than 1 of the 50 states, including Rhode Island (1,033.9 square miles of land).
How many acres of land are in Bannock County?
The land measurement converts to approximately 711,993 acres. Including water, total area is approximately 734,746 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.