Sedgwick County area

Sedgwick County, Colorado covers 549.4 square miles: 548 square miles of land and 1.363 square miles of water. Its county seat is Julesburg. An estimated 2,247 people lived there in 2025.

Official Census measurements · GEOID 081152026 Gazetteer · retrieved September 27, 2026
Land area548 mi²
Water area1.363 mi²
Population (2025)2,247
People per mi²4.1

County outline

Generalized outline of Sedgwick County, Colorado
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 Sedgwick County is located

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

Area breakdown

Land accounts for 99.8% of Sedgwick County’s measured area and water for 0.2%. Its combined area converts to 1,422.9 square kilometers or approximately 351,619 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land548.0411,419.42350,746.2
Water1.3633.53872.3
Total549.4041,422.95351,618.6

How Sedgwick County compares

By original Census land area, Sedgwick County ranks #57 of 64 in Colorado and #1904 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 0.383 times the Colorado county-equivalent median of 1,431.5 square miles. It accounts for 0.5% of the combined county land area in the state.

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

Population and density of Sedgwick County

The Census Bureau estimates that 2,247 people lived in Sedgwick County on July 1, 2025. That ranks #3,101 of 3,222 county equivalents nationally and #58 of 64 in Colorado. Since the April 1, 2020 estimates base of 2,404, the population has declined by 157 (−6.5%), compared with +4.1% for Colorado as a whole.

With 548 square miles of land, that is 4.1 people per square mile (1.6 per km²), placing Sedgwick County #2,898 nationally for density and #47 in Colorado. The median county equivalent has 47 people per square mile; the Colorado median is 11. Put another way, there are about 156 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate2,3912,3272,2902,3132,2712,247
Change—−64−37+23−42−24

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 Sedgwick County

3 incorporated places lie at least partly in Sedgwick County. Together they are home to 1,635 people (72.8%); the other 612 (27.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Julesburg town, with 1,217 residents in the county.

Incorporated placePopulation 2025Since 2020Land mi²
Julesburg townCounty seat1,217−6.8%1.512
Ovid town256−5.5%0.156
Sedgwick town162−6.9%0.389

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

Metropolitan area

Sedgwick 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 Sedgwick County; 3 of them have most of their land inside the county, and the others mainly cover neighboring areas.

6916880731807378074480749

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 Sedgwick County

Sedgwick County shares a land border with 5 county equivalents, including 3 in Nebraska. It has more land than 1 of them. The largest neighbor is Logan County (1,838.6 mi²) and the smallest is Deuel County (439.8 mi²). Together with its neighbors, Sedgwick County forms a block of 5,593.7 mi² of land, of which it holds 9.8%.

Map of Sedgwick County and the 5 county equivalents that border it Phillips County, Colorado: 687.9 mi² landDeuel County, Nebraska: 439.8 mi² landPerkins County, Nebraska: 883.3 mi² landLogan County, Colorado: 1,838.6 mi² landCheyenne County, Nebraska: 1,196 mi² land
Sedgwick 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. SedgwickCompare
Logan County1,838.63.4× largerCompare
Cheyenne CountyNebraska1,1962.2× largerCompare
Perkins CountyNebraska883.31.6× largerCompare
Phillips County687.91.3× largerCompare
Deuel CountyNebraska439.81.2× smallerCompare

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

Sedgwick County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 1.9 times as much. Colorado’s county land could hold about 189 areas the size of Sedgwick County.

Land area: Sedgwick County and the closest-sized states
Sedgwick County548 mi²
Rhode Island1,033.9 mi²

Another way to picture it: the same land area would fill a square about 23.4 miles (37.7 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 Sedgwick County?

Sedgwick County has more land than 1,318 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Sedgwick County548 mi²
Colorado median1,431.5 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 Sedgwick County at #2,008 nationally by total area, 104 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 0.2%, compared with a national county-equivalent median of 1.2% — 0.9 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 Sedgwick County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#1903Barnwell County, South Carolina548.4Compare
#1904Sedgwick County, Colorado548This county
#1905Grant County, Minnesota547.8Compare

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 40.871568, -102.355358. 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: 1,419,419,017 m²; AWATER: 3,530,746 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 Sedgwick County?

Sedgwick County, Colorado has 548 square miles (1,419.4 km²) of land and 1.363 square miles of water, for a total area of 549.4 square miles. It ranks #1904 of 3,222 U.S. county equivalents by land area.

Is Sedgwick County the largest county in Colorado?

No. Sedgwick County ranks #57 of 64 in Colorado by land area. The largest is Las Animas County, with 4,772.9 square miles of land.

What counties border Sedgwick County?

Sedgwick County shares a land border with Phillips County, Deuel County, Nebraska, Perkins County, Nebraska, Logan County, and Cheyenne County, Nebraska.

What is the population of Sedgwick County?

The Census Bureau estimates Sedgwick County had 2,247 residents on July 1, 2025, ranking #3,101 of 3,222 county equivalents. That is 4.1 people per square mile of land.

What is the county seat of Sedgwick County?

The county seat of Sedgwick County is Julesburg.

What cities and towns are in Sedgwick County?

Sedgwick County has 3 incorporated places. The most populous are Julesburg town, Ovid town, and Sedgwick town; 612 residents live outside any incorporated place.

Is Sedgwick County part of a metropolitan area?

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

How many ZIP codes are in Sedgwick County?

5 ZIP Code Tabulation Areas have land in Sedgwick 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 Sedgwick County compare with U.S. states?

It has less land than every state. Rhode Island, the smallest, has 1.9 times as much land.

How many acres of land are in Sedgwick County?

The land measurement converts to approximately 350,746 acres. Including water, total area is approximately 351,619 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

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