Powder River County area

Powder River County, Montana covers 3,298.8 square miles: 3,298.2 square miles of land and 0.605 square miles of water. Its county seat is Broadus. An estimated 1,781 people lived there in 2025.

Official Census measurements · GEOID 300752026 Gazetteer · retrieved September 27, 2026
Land area3,298.2 mi²
Water area0.605 mi²
Population (2025)1,781
People per mi²0.54

County outline

Generalized outline of Powder River County, Montana
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 Powder River County is located

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

Area breakdown

Land accounts for 100% of Powder River County’s measured area and water for 0%. Its combined area converts to 8,543.9 square kilometers or approximately 2,111,233 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land3,298.1968,542.2882,110,845.4
Water0.6051.567387.2
Total3,298.8018,543.8552,111,232.6

How Powder River County compares

By original Census land area, Powder River County ranks #16 of 56 in Montana and #154 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 1.396 times the Montana county-equivalent median of 2,363.3 square miles. It accounts for 2.3% of the combined county land area in the state.

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

Population and density of Powder River County

The Census Bureau estimates that 1,781 people lived in Powder River County on July 1, 2025. That ranks #3,138 of 3,222 county equivalents nationally and #47 of 56 in Montana. Since the April 1, 2020 estimates base of 1,695, the population has grown by 86 (+5.1%), compared with +5.6% for Montana as a whole.

With 3,298.2 square miles of land, that is 0.54 people per square mile (0.21 per km²), placing Powder River County #3,192 nationally for density and #53 in Montana. The median county equivalent has 47 people per square mile; the Montana median is 2.8. Put another way, there are about 1,185 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate1,6941,7101,7281,7441,7581,781
Change—+16+18+16+14+23

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 Powder River County

1 incorporated place lies at least partly in Powder River County. Together they are home to 477 people (26.8%); the other 1,304 (73.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Broadus town, with 477 residents in the county.

Metropolitan area

Powder River 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

9 ZIP Code Tabulation Areas have land in Powder River County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.

590035906259301593145931659317593435934559351

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 Powder River County

Powder River County shares a land border with 7 county equivalents, including 3 in Wyoming. It has more land than 2 of them. The largest neighbor is Rosebud County (5,008.1 mi²) and the smallest is Sheridan County (2,523.4 mi²). Together with its neighbors, Powder River County forms a block of 30,607.8 mi² of land, of which it holds 10.8%.

Map of Powder River County and the 7 county equivalents that border it Custer County, Montana: 3,783.3 mi² landCarter County, Montana: 3,340.5 mi² landCampbell County, Wyoming: 4,802.1 mi² landRosebud County, Montana: 5,008.1 mi² landBig Horn County, Montana: 4,997.8 mi² landSheridan County, Wyoming: 2,523.4 mi² landCrook County, Wyoming: 2,854.5 mi² land
Powder River 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. Powder RiverCompare
Rosebud County5,008.11.5× largerCompare
Big Horn County4,997.81.5× largerCompare
Campbell CountyWyoming4,802.11.5× largerCompare
Custer County3,783.31.1× largerCompare
Carter County3,340.5about the sameCompare
Crook CountyWyoming2,854.51.2× smallerCompare
Sheridan CountyWyoming2,523.41.3× smallerCompare

How big is Powder River County compared with U.S. states?

Powder River County has more land than 2 of the 50 states. It is about 1.7 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.5 times as much land (4,842.5 mi²). Montana’s county land could hold about 44 areas the size of Powder River County.

Land area: Powder River County and the closest-sized states
Delaware1,948.6 mi²
Powder River County3,298.2 mi²
Connecticut4,842.5 mi²

Another way to picture it: the same land area would fill a square about 57.4 miles (92.4 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 Powder River County?

Powder River County has more land than 3,068 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Powder River County3,298.2 mi²
Montana median2,363.3 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 Powder River County at #166 nationally by total area, 12 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 0%, compared with a national county-equivalent median of 1.2% — 1.2 percentage points lower. 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 Powder River County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#153San Luis Obispo County, California3,300.8Compare
#154Powder River County, Montana3,298.2This county
#155Iron County, Utah3,296.2Compare

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 45.408926, -105.555344. 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: 8,542,288,789 m²; AWATER: 1,565,957 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 Powder River County?

Powder River County, Montana has 3,298.2 square miles (8,542.3 km²) of land and 0.605 square miles of water, for a total area of 3,298.8 square miles. It ranks #154 of 3,222 U.S. county equivalents by land area.

Is Powder River County the largest county in Montana?

No. Powder River County ranks #16 of 56 in Montana by land area. The largest is Beaverhead County, with 5,542.7 square miles of land.

What counties border Powder River County?

Powder River County shares a land border with Custer County, Carter County, Campbell County, Wyoming, Rosebud County, Big Horn County, Sheridan County, Wyoming, and Crook County, Wyoming.

What is the population of Powder River County?

The Census Bureau estimates Powder River County had 1,781 residents on July 1, 2025, ranking #3,138 of 3,222 county equivalents. That is 0.54 people per square mile of land.

What is the county seat of Powder River County?

The county seat of Powder River County is Broadus.

Is Powder River County part of a metropolitan area?

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

How many ZIP codes are in Powder River County?

9 ZIP Code Tabulation Areas have land in Powder River County, and 7 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Powder River County compare with U.S. states?

It has more land than 2 of the 50 states, including Delaware (1,948.6 square miles of land).

How many acres of land are in Powder River County?

The land measurement converts to approximately 2,110,845 acres. Including water, total area is approximately 2,111,233 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