Hyde County area

Hyde County, South Dakota covers 866.2 square miles: 860.6 square miles of land and 5.615 square miles of water. Its county seat is Highmore. An estimated 1,191 people lived there in 2025.

Official Census measurements · GEOID 460692026 Gazetteer · retrieved September 27, 2026
Land area860.6 mi²
Water area5.615 mi²
Population (2025)1,191
People per mi²1.4

County outline

Generalized outline of Hyde County, South Dakota
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 Hyde County is located

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

Area breakdown

Land accounts for 99.4% of Hyde County’s measured area and water for 0.6%. Its combined area converts to 2,243.6 square kilometers or approximately 554,396 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land860.6292,229.019550,802.6
Water5.61514.5433,593.6
Total866.2442,243.562554,396.2

How Hyde County compares

By original Census land area, Hyde County ranks #35 of 66 in South Dakota and #965 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.946 times the South Dakota county-equivalent median of 909.3 square miles. It accounts for 1.1% 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 Hyde County

The Census Bureau estimates that 1,191 people lived in Hyde County on July 1, 2025. That ranks #3,175 of 3,222 county equivalents nationally and #65 of 66 in South Dakota. Since the April 1, 2020 estimates base of 1,259, the population has declined by 68 (−5.4%), compared with +5.5% for South Dakota as a whole.

With 860.6 square miles of land, that is 1.4 people per square mile (0.53 per km²), placing Hyde County #3,115 nationally for density and #61 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 462 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate1,2481,2281,1901,1831,2091,191
Change—−20−38−7+26−18

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 Hyde County

1 incorporated place lies at least partly in Hyde County. Together they are home to 634 people (53.2%); the other 557 (46.8%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Highmore city, with 634 residents in the county.

Metropolitan area

Hyde 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

5 ZIP Code Tabulation Areas have land in Hyde County; 3 of them have most of their land inside the county, and the others mainly cover neighboring areas.

5734557346573715754057564

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 Hyde County

Hyde County shares a land border with 7 county equivalents. It has more land than 2 of them. The largest neighbor is Lyman County (1,642.3 mi²) and the smallest is Buffalo County (471.4 mi²). Together with its neighbors, Hyde County forms a block of 8,002.1 mi² of land, of which it holds 10.8%.

Map of Hyde County and the 7 county equivalents that border it Hand County, South Dakota: 1,436.6 mi² landSully County, South Dakota: 1,006.7 mi² landHughes County, South Dakota: 741.5 mi² landBuffalo County, South Dakota: 471.4 mi² landFaulk County, South Dakota: 981.7 mi² landPotter County, South Dakota: 861.1 mi² landLyman County, South Dakota: 1,642.3 mi² land
Hyde 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. HydeCompare
Lyman County1,642.31.9× largerCompare
Hand County1,436.61.7× largerCompare
Sully County1,006.71.2× largerCompare
Faulk County981.71.1× largerCompare
Potter County861.1about the sameCompare
Hughes County741.51.2× smallerCompare
Buffalo County471.41.8× smallerCompare

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

Hyde County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.2 times as much. South Dakota’s county land could hold about 88 areas the size of Hyde County.

Land area: Hyde County and the closest-sized states
Hyde County860.6 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 29.3 miles (47.2 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 Hyde County?

Hyde County has more land than 2,257 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Hyde County860.6 mi²
South Dakota median909.3 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 Hyde County at #1,051 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 0.6%, compared with a national county-equivalent median of 1.2% — 0.5 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 Hyde County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#964Potter County, South Dakota861.1Compare
#965Hyde County, South Dakota860.6This county
#966Hodgeman County, Kansas860Compare

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 44.537174, -99.472736. 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: 2,229,019,395 m²; AWATER: 14,541,548 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 Hyde County?

Hyde County, South Dakota has 860.6 square miles (2,229 km²) of land and 5.615 square miles of water, for a total area of 866.2 square miles. It ranks #965 of 3,222 U.S. county equivalents by land area.

Is Hyde County the largest county in South Dakota?

No. Hyde County ranks #35 of 66 in South Dakota by land area. The largest is Meade County, with 3,470.9 square miles of land.

What counties border Hyde County?

Hyde County shares a land border with Hand County, Sully County, Hughes County, Buffalo County, Faulk County, Potter County, and Lyman County.

What is the population of Hyde County?

The Census Bureau estimates Hyde County had 1,191 residents on July 1, 2025, ranking #3,175 of 3,222 county equivalents. That is 1.4 people per square mile of land.

What is the county seat of Hyde County?

The county seat of Hyde County is Highmore.

Is Hyde County part of a metropolitan area?

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

How many ZIP codes are in Hyde County?

5 ZIP Code Tabulation Areas have land in Hyde County, and 3 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Hyde County compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 1.2 times as much land.

How many acres of land are in Hyde County?

The land measurement converts to approximately 550,803 acres. Including water, total area is approximately 554,396 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