County outline
Where Gregory County is located
Area breakdown
Land accounts for 96.3% of Gregory County’s measured area and water for 3.7%. Its combined area converts to 2,728.6 square kilometers or approximately 674,254 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 1,014.95 | 2,628.708 | 649,568 |
| Water | 38.572 | 99.901 | 24,686.1 |
| Total | 1,053.522 | 2,728.609 | 674,254.1 |
How Gregory County compares
By original Census land area, Gregory County ranks #29 of 66 in South Dakota and #660 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.116 times the South Dakota county-equivalent median of 909.3 square miles. It accounts for 1.3% of the combined county land area in the state.
See the complete South Dakota ranking · What counts as a county equivalent?
Population and density of Gregory County
The Census Bureau estimates that 4,037 people lived in Gregory County on July 1, 2025. That ranks #2,960 of 3,222 county equivalents nationally and #39 of 66 in South Dakota. Since the April 1, 2020 estimates base of 3,987, the population has grown by 50 (+1.3%), compared with +5.5% for South Dakota as a whole.
With 1,015 square miles of land, that is 4 people per square mile (1.5 per km²), placing Gregory County #2,908 nationally for density and #42 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 161 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 3,993 | 3,948 | 3,985 | 4,008 | 4,071 | 4,037 |
| Change | — | −45 | +37 | +23 | +63 | −34 |
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 Gregory County
6 incorporated places lie at least partly in Gregory County. Together they are home to 2,357 people (58.4%); the other 1,680 (41.6%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Gregory city, with 1,250 residents in the county. The county seat, Burke city, has 590 residents.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Gregory city | 1,250 | +2.9% | 1.721 |
| Burke cityCounty seat | 590 | −0.7% | 0.559 |
| Bonesteel city | 257 | +0.8% | 0.354 |
| Fairfax town | 100 | +3.1% | 0.303 |
| Dallas town | 83 | −1.2% | 0.507 |
| Herrick town | 77 | 0% | 0.515 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Gregory County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Gregory 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 Gregory County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
573175733557523575295753357538575716871968755
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 Gregory County
Gregory County shares a land border with 5 county equivalents, including 2 in Nebraska. It has more land than 2 of them. The largest neighbor is Lyman County (1,642.3 mi²) and the smallest is Boyd County (539.4 mi²). Together with its neighbors, Gregory County forms a block of 6,678.9 mi² of land, of which it holds 15.2%.
| Bordering county equivalent | Land mi² | Size vs. Gregory | Compare |
|---|---|---|---|
| Lyman County | 1,642.3 | 1.6× larger | Compare |
| Tripp County | 1,612.3 | 1.6× larger | Compare |
| Charles Mix County | 1,097.1 | 1.1× larger | Compare |
| Keya Paha CountyNebraska | 772.9 | 1.3× smaller | Compare |
| Boyd CountyNebraska | 539.4 | 1.9× smaller | Compare |
How big is Gregory County compared with U.S. states?
Gregory 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 times as much. South Dakota’s county land could hold about 75 areas the size of Gregory County.
Another way to picture it: the same land area would fill a square about 31.9 miles (51.3 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 Gregory County?
Gregory County has more land than 2,562 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 Gregory County at #717 nationally by total area, 57 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 3.7%, compared with a national county-equivalent median of 1.2% — 2.5 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 Gregory County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #659 | Brevard County, Florida | 1,015 | Compare |
| #660 | Gregory County, South Dakota | 1,015 | This county |
| #661 | Forest County, Wisconsin | 1,014.3 | 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 43.175142, -99.206591. 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: 2,628,707,538 m²; AWATER: 99,900,711 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 Gregory County?
Gregory County, South Dakota has 1,015 square miles (2,628.7 km²) of land and 38.6 square miles of water, for a total area of 1,053.5 square miles. It ranks #660 of 3,222 U.S. county equivalents by land area.
Is Gregory County the largest county in South Dakota?
No. Gregory County ranks #29 of 66 in South Dakota by land area. The largest is Meade County, with 3,470.9 square miles of land.
What counties border Gregory County?
Gregory County shares a land border with Charles Mix County, Boyd County, Nebraska, Tripp County, Keya Paha County, Nebraska, and Lyman County.
What is the population of Gregory County?
The Census Bureau estimates Gregory County had 4,037 residents on July 1, 2025, ranking #2,960 of 3,222 county equivalents. That is 4 people per square mile of land.
What is the county seat of Gregory County?
The county seat of Gregory County is Burke.
What cities and towns are in Gregory County?
Gregory County has 6 incorporated places. The most populous five are Gregory city, Burke city, Bonesteel city, Fairfax town, and Dallas town; 1,680 residents live outside any incorporated place.
Is Gregory County part of a metropolitan area?
No. Gregory County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Gregory County?
9 ZIP Code Tabulation Areas have land in Gregory County, and 6 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Gregory County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 1 times as much land.
How many acres of land are in Gregory County?
The land measurement converts to approximately 649,568 acres. Including water, total area is approximately 674,254 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.