County outline
Where Crook County is located
Area breakdown
Land accounts for 99.6% of Crook County’s measured area and water for 0.4%. Its combined area converts to 7,421.3 square kilometers or approximately 1,833,832 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 2,854.48 | 7,393.069 | 1,826,867.2 |
| Water | 10.883 | 28.187 | 6,965.1 |
| Total | 2,865.363 | 7,421.256 | 1,833,832.3 |
How Crook County compares
By original Census land area, Crook County ranks #14 of 23 in Wyoming and #183 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.714 times the Wyoming county-equivalent median of 3,996.8 square miles. It accounts for 2.9% of the combined county land area in the state.
See the complete Wyoming ranking · What counts as a county equivalent?
Population and density of Crook County
The Census Bureau estimates that 7,852 people lived in Crook County on July 1, 2025. That ranks #2,661 of 3,222 county equivalents nationally and #19 of 23 in Wyoming. Since the April 1, 2020 estimates base of 7,182, the population has grown by 670 (+9.3%), compared with +2.1% for Wyoming as a whole.
With 2,854.5 square miles of land, that is 2.8 people per square mile (1.1 per km²), placing Crook County #3,003 nationally for density and #18 in Wyoming. The median county equivalent has 47 people per square mile; the Wyoming median is 4.1. Put another way, there are about 233 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 7,183 | 7,311 | 7,418 | 7,591 | 7,791 | 7,852 |
| Change | — | +128 | +107 | +173 | +200 | +61 |
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 Crook County
4 incorporated places lie at least partly in Crook County. Together they are home to 3,092 people (39.4%); the other 4,760 (60.6%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Sundance town, with 1,141 residents in the county.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Sundance townCounty seat | 1,141 | +10.5% | 3.051 |
| Moorcroft town | 1,023 | +8.5% | 1.263 |
| Pine Haven town | 579 | +17.2% | 1.317 |
| Hulett town | 349 | +12.2% | 0.894 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Crook County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Crook 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
10 ZIP Code Tabulation Areas have land in Crook County; 7 of them have most of their land inside the county, and the others mainly cover neighboring areas.
57717827108271182712827148272082721827278272982730
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 Crook County
Crook County shares a land border with 6 county equivalents, including 4 in Montana and South Dakota. It has more land than 3 of them. The largest neighbor is Campbell County (4,802.1 mi²) and the smallest is Lawrence County (800.1 mi²). Together with its neighbors, Crook County forms a block of 19,743.3 mi² of land, of which it holds 14.5%.
| Bordering county equivalent | Land mi² | Size vs. Crook | Compare |
|---|---|---|---|
| Campbell County | 4,802.1 | 1.7× larger | Compare |
| Carter CountyMontana | 3,340.5 | 1.2× larger | Compare |
| Powder River CountyMontana | 3,298.2 | 1.2× larger | Compare |
| Weston County | 2,398 | 1.2× smaller | Compare |
| Butte CountySouth Dakota | 2,250 | 1.3× smaller | Compare |
| Lawrence CountySouth Dakota | 800.1 | 3.6× smaller | Compare |
How big is Crook County compared with U.S. states?
Crook County has more land than 2 of the 50 states. It is about 1.5 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.7 times as much land (4,842.5 mi²). Wyoming’s county land could hold about 34 areas the size of Crook County.
Another way to picture it: the same land area would fill a square about 53.4 miles (86 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 Crook County?
Crook County has more land than 3,039 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 Crook County at #196 nationally by total area, 13 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 0.4%, compared with a national county-equivalent median of 1.2% — 0.8 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 Crook County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #182 | Sitka City and Borough, Alaska | 2,870.3 | Compare |
| #183 | Crook County, Wyoming | 2,854.5 | This county |
| #184 | Crockett County, Texas | 2,807.3 | 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 44.589266, -104.567298. 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: 7,393,068,910 m²; AWATER: 28,186,052 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 Crook County?
Crook County, Wyoming has 2,854.5 square miles (7,393.1 km²) of land and 10.9 square miles of water, for a total area of 2,865.4 square miles. It ranks #183 of 3,222 U.S. county equivalents by land area.
Is Crook County the largest county in Wyoming?
No. Crook County ranks #14 of 23 in Wyoming by land area. The largest is Sweetwater County, with 10,427 square miles of land.
What counties border Crook County?
Crook County shares a land border with Campbell County, Weston County, Carter County, Montana, Butte County, South Dakota, Lawrence County, South Dakota, and Powder River County, Montana.
What is the population of Crook County?
The Census Bureau estimates Crook County had 7,852 residents on July 1, 2025, ranking #2,661 of 3,222 county equivalents. That is 2.8 people per square mile of land.
What is the county seat of Crook County?
The county seat of Crook County is Sundance.
What cities and towns are in Crook County?
Crook County has 4 incorporated places. The most populous are Sundance town, Moorcroft town, Pine Haven town, and Hulett town; 4,760 residents live outside any incorporated place.
Is Crook County part of a metropolitan area?
No. Crook County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Crook County?
10 ZIP Code Tabulation Areas have land in Crook County, and 7 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Crook County compare with U.S. states?
It has more land than 2 of the 50 states, including Delaware (1,948.6 square miles of land).
How many acres of land are in Crook County?
The land measurement converts to approximately 1,826,867 acres. Including water, total area is approximately 1,833,832 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.