Power County area

Power County, Idaho covers 1,442.1 square miles: 1,403.8 square miles of land and 38.3 square miles of water. Its county seat is American Falls. An estimated 8,246 people lived there in 2025.

Official Census measurements · GEOID 160772026 Gazetteer · retrieved September 27, 2026
Land area1,403.8 mi²
Water area38.3 mi²
Population (2025)8,246
People per mi²5.9

County outline

Generalized outline of Power County, Idaho
2025 Census cartographic boundary, fitted to this frame. County maps are not at a common scale. The 2026 area measurements below come from the separate Gazetteer release. Map source and limitations.

Where Power County is located

Power County highlighted on a map of all U.S. county equivalents. About the maps

Area breakdown

Land accounts for 97.3% of Power County’s measured area and water for 2.7%. Its combined area converts to 3,735.1 square kilometers or approximately 922,963 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land1,403.8263,635.893898,448.6
Water38.30399.20424,513.9
Total1,442.1293,735.097922,962.6

How Power County compares

By original Census land area, Power County ranks #21 of 44 in Idaho and #429 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.067 times the Idaho county-equivalent median of 1,315.7 square miles. It accounts for 1.7% of the combined county land area in the state.

See the complete Idaho ranking · What counts as a county equivalent?

Population and density of Power County

The Census Bureau estimates that 8,246 people lived in Power County on July 1, 2025. That ranks #2,632 of 3,222 county equivalents nationally and #34 of 44 in Idaho. Since the April 1, 2020 estimates base of 7,877, the population has grown by 369 (+4.7%), compared with +10.4% for Idaho as a whole.

With 1,403.8 square miles of land, that is 5.9 people per square mile (2.3 per km²), placing Power County #2,808 nationally for density and #29 in Idaho. The median county equivalent has 47 people per square mile; the Idaho median is 10. Put another way, there are about 109 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate7,8807,9828,1308,2928,3338,246
Change—+102+148+162+41−87

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 Power County

3 incorporated places lie at least partly in Power County. Together they are home to 5,042 people (61.1%); the other 3,204 (38.9%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is American Falls city, with 4,785 residents in the county. By land, Pocatello city is the largest at 34.9 mi² across all its counties.

Incorporated placePopulation 2025Since 2020Land mi²
American Falls cityCounty seat4,785+4.8%1.614
Rockland city257+7.5%0.299
Pocatello cityAlso in 1 other county0—34.9

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Power County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Power County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.

ZIP codes

4 ZIP Code Tabulation Areas have land in Power County, and each lies mostly inside the county.

83204832118321283271

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Power County

Power County shares a land border with 5 county equivalents. It has more land than 2 of them. The largest neighbor is Blaine County (2,637.7 mi²) and the smallest is Bannock County (1,112.5 mi²). Together with its neighbors, Power County forms a block of 11,012.3 mi² of land, of which it holds 12.7%.

Map of Power County and the 5 county equivalents that border it Blaine County, Idaho: 2,637.7 mi² landBannock County, Idaho: 1,112.5 mi² landOneida County, Idaho: 1,199 mi² landBingham County, Idaho: 2,093.7 mi² landCassia County, Idaho: 2,565.6 mi² land
Power County (dark) and its bordering county equivalents. Select a neighbor to open its profile. Drawn from the 2025 Census cartographic boundaries in an equal-area projection. How borders are determined.
Bordering county equivalentLand mi²Size vs. PowerCompare
Blaine County2,637.71.9× largerCompare
Cassia County2,565.61.8× largerCompare
Bingham County2,093.71.5× largerCompare
Oneida County1,1991.2× smallerCompare
Bannock County1,112.51.3× smallerCompare

How big is Power County compared with U.S. states?

Power County has more land than 1 of the 50 states. It is about 1.4 times the land area of Rhode Island (1,033.9 mi²), while Delaware, the next larger state, has 1.4 times as much land (1,948.6 mi²). Idaho’s county land could hold about 59 areas the size of Power County.

Land area: Power County and the closest-sized states
Rhode Island1,033.9 mi²
Power County1,403.8 mi²
Delaware1,948.6 mi²

Another way to picture it: the same land area would fill a square about 37.5 miles (60.3 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 Power County?

Power County has more land than 2,793 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Power County1,403.8 mi²
Idaho median1,315.7 mi²
National median604.5 mi²

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 Power County at #474 nationally by total area, 45 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 2.7%, compared with a national county-equivalent median of 1.2% — 1.5 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 Power County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#428Curry County, New Mexico1,405.5Compare
#429Power County, Idaho1,403.8This county
#430Pend Oreille County, Washington1,400.2Compare

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 42.694126, -112.844407. 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: 3,635,892,309 m²; AWATER: 99,205,459 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.

Download the official county source ZIP ↗ · Methodology

Common questions

How big is Power County?

Power County, Idaho has 1,403.8 square miles (3,635.9 km²) of land and 38.3 square miles of water, for a total area of 1,442.1 square miles. It ranks #429 of 3,222 U.S. county equivalents by land area.

Is Power County the largest county in Idaho?

No. Power County ranks #21 of 44 in Idaho by land area. The largest is Idaho County, with 8,477.5 square miles of land.

What counties border Power County?

Power County shares a land border with Blaine County, Bannock County, Oneida County, Bingham County, and Cassia County.

What is the population of Power County?

The Census Bureau estimates Power County had 8,246 residents on July 1, 2025, ranking #2,632 of 3,222 county equivalents. That is 5.9 people per square mile of land.

What is the county seat of Power County?

The county seat of Power County is American Falls.

What cities and towns are in Power County?

Power County has 3 incorporated places. The most populous are American Falls city, Rockland city, and Pocatello city; 3,204 residents live outside any incorporated place.

Is Power County part of a metropolitan area?

No. Power County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.

How many ZIP codes are in Power County?

4 ZIP Code Tabulation Areas have land in Power County, and 4 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Power 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 Power County?

The land measurement converts to approximately 898,449 acres. Including water, total area is approximately 922,963 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.

Cite this county

Download the complete CSV or JSON dataset