Brookings County area

Population and density of Brookings County

The Census Bureau estimates that 37,635 people lived in Brookings County on July 1, 2025. That ranks #1,277 of 3,222 county equivalents nationally and #4 of 66 in South Dakota. Since the April 1, 2020 estimates base of 34,364, the population has grown by 3,271 (+9.5%), compared with +5.5% for South Dakota as a whole.

With 792.2 square miles of land, that is 48 people per square mile (18 per km²), placing Brookings County #1,604 nationally for density and #3 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 13 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 Brookings County

9 incorporated places lie at least partly in Brookings County. Together they are home to 30,875 people (82%); the other 6,760 (18%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Brookings city, with 25,355 residents in the county. Among places with at least 1,000 residents in 2020, Aurora town grew fastest since then (+22.6%).

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

Metropolitan area

Brookings County is a central county of the Brookings, SD Micropolitan Statistical Area. Brookings County is the area’s only county equivalent, so the micro area has the same 792.2 square miles of land. By combined land it ranks #269 of 542 micropolitan areas, and #357 by population.

ZIP codes

13 ZIP Code Tabulation Areas have land in Brookings County; 8 of them have most of their land inside the county, and the others mainly cover neighboring areas.

56136570025700657007570265706157071572125721357220572345726857276

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 Brookings County

Brookings County shares a land border with 6 county equivalents, including 1 in Minnesota. It has more land than 5 of them. The largest neighbor is Kingsbury County (832.2 mi²) and the smallest is Hamlin County (507.1 mi²). Together with its neighbors, Brookings County forms a block of 4,373.3 mi² of land, of which it holds 18.1%.

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

Brookings County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.3 times as much. South Dakota’s county land could hold about 96 areas the size of Brookings County.

Another way to picture it: the same land area would fill a square about 28.1 miles (45.3 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 Brookings County?

Brookings County has more land than 2,139 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 Brookings County at #1,169 nationally by total area, 86 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 1.6%, compared with a national county-equivalent median of 1.2% — 0.4 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 Brookings 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.