Stanley County area

Population and density of Stanley County

The Census Bureau estimates that 3,018 people lived in Stanley County on July 1, 2025. That ranks #3,033 of 3,222 county equivalents nationally and #47 of 66 in South Dakota. Since the April 1, 2020 estimates base of 2,978, the population has grown by 40 (+1.3%), compared with +5.5% for South Dakota as a whole.

With 1,444.4 square miles of land, that is 2.1 people per square mile (0.81 per km²), placing Stanley County #3,059 nationally for density and #54 in South Dakota. The median county equivalent has 47 people per square mile; the South Dakota median is 5.7. Put another way, there are about 306 acres of land per resident.

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 Stanley County

1 incorporated place lies at least partly in Stanley County. Together they are home to 2,166 people (71.8%); the other 852 (28.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Fort Pierre city, with 2,166 residents in the county.

Metropolitan area

Stanley County is a central county of the Pierre, SD Micropolitan Statistical Area. Its 2 county equivalents have 20,588 residents on 2,186 square miles of land; Stanley County accounts for 66.1% of the land and 14.7% of the residents. By combined land it ranks #72 of 542 micropolitan areas, and #511 by population.

ZIP codes

4 ZIP Code Tabulation Areas have land in Stanley County; 2 of them have most of their land inside the county, and the others mainly cover neighboring areas.

57531575325753757552

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 Stanley County

Stanley County shares a land border with 6 county equivalents. It has more land than 3 of them. The largest neighbor is Dewey County (2,302.4 mi²) and the smallest is Hughes County (741.5 mi²). Together with its neighbors, Stanley County forms a block of 9,917.6 mi² of land, of which it holds 14.6%.

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

Stanley 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 1.3 times as much land (1,948.6 mi²). South Dakota’s county land could hold about 52 areas the size of Stanley County.

Another way to picture it: the same land area would fill a square about 38 miles (61.2 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 Stanley County?

Stanley County has more land than 2,807 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 Stanley County at #439 nationally by total area, 24 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 4.8%, compared with a national county-equivalent median of 1.2% — 3.6 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 Stanley County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

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.