County outline
Where Garfield County is located
Area breakdown
Land accounts for 96.4% of Garfield County’s measured area and water for 3.6%. Its combined area converts to 12,559.1 square kilometers or approximately 3,103,421 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 4,676.56 | 12,112.235 | 2,992,998.4 |
| Water | 172.535 | 446.864 | 110,422.4 |
| Total | 4,849.095 | 12,559.098 | 3,103,420.8 |
How Garfield County compares
By original Census land area, Garfield County ranks #7 of 56 in Montana and #93 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.979 times the Montana county-equivalent median of 2,363.3 square miles. It accounts for 3.2% of the combined county land area in the state.
See the complete Montana ranking · What counts as a county equivalent?
Population and density of Garfield County
The Census Bureau estimates that 1,148 people lived in Garfield County on July 1, 2025. That ranks #3,179 of 3,222 county equivalents nationally and #51 of 56 in Montana. Since the April 1, 2020 estimates base of 1,170, the population has declined by 22 (−1.9%), compared with +5.6% for Montana as a whole.
With 4,676.6 square miles of land, that is 0.25 people per square mile (0.095 per km²), placing Garfield County #3,210 nationally for density and #56 in Montana. The median county equivalent has 47 people per square mile; the Montana median is 2.8. Put another way, there are about 2,607 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 1,170 | 1,206 | 1,220 | 1,210 | 1,175 | 1,148 |
| Change | — | +36 | +14 | −10 | −35 | −27 |
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 Garfield County
1 incorporated place lies at least partly in Garfield County. Together they are home to 348 people (30.3%); the other 800 (69.7%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Jordan town, with 348 residents in the county.
Metropolitan area
Garfield 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 Garfield County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
590585907759214592235930159312593185932259337
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 Garfield County
Garfield County shares a land border with 7 county equivalents. It has more land than 4 of them. The largest neighbor is Phillips County (5,140.4 mi²) and the smallest is Petroleum County (1,655.6 mi²). Together with its neighbors, Garfield County forms a block of 29,569 mi² of land, of which it holds 15.8%.
| Bordering county equivalent | Land mi² | Size vs. Garfield | Compare |
|---|---|---|---|
| Phillips County | 5,140.4 | 1.1× larger | Compare |
| Rosebud County | 5,008.1 | 1.1× larger | Compare |
| Valley County | 4,926.1 | 1.1× larger | Compare |
| Custer County | 3,783.3 | 1.2× smaller | Compare |
| McCone County | 2,642.2 | 1.8× smaller | Compare |
| Prairie County | 1,736.6 | 2.7× smaller | Compare |
| Petroleum County | 1,655.6 | 2.8× smaller | Compare |
How big is Garfield County compared with U.S. states?
Garfield County has more land than 2 of the 50 states. It is about 2.4 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1 times as much land (4,842.5 mi²). Montana’s county land could hold about 31 areas the size of Garfield County.
Another way to picture it: the same land area would fill a square about 68.4 miles (110.1 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 Garfield County?
Garfield County has more land than 3,129 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 Garfield County at #90 nationally by total area, 3 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.
Its water share is 3.6%, compared with a national county-equivalent median of 1.2% — 2.4 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 Garfield County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #92 | San Miguel County, New Mexico | 4,721.5 | Compare |
| #93 | Garfield County, Montana | 4,676.6 | This county |
| #94 | Graham County, Arizona | 4,621.9 | 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 47.267184, -106.995991. 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: 12,112,233,221 m²; AWATER: 446,864,508 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 Garfield County?
Garfield County, Montana has 4,676.6 square miles (12,112.2 km²) of land and 172.5 square miles of water, for a total area of 4,849.1 square miles. It ranks #93 of 3,222 U.S. county equivalents by land area.
Is Garfield County the largest county in Montana?
No. Garfield County ranks #7 of 56 in Montana by land area. The largest is Beaverhead County, with 5,542.7 square miles of land.
What counties border Garfield County?
Garfield County shares a land border with Rosebud County, McCone County, Valley County, Petroleum County, Phillips County, Prairie County, and Custer County.
What is the population of Garfield County?
The Census Bureau estimates Garfield County had 1,148 residents on July 1, 2025, ranking #3,179 of 3,222 county equivalents. That is 0.25 people per square mile of land.
What is the county seat of Garfield County?
The county seat of Garfield County is Jordan.
Is Garfield County part of a metropolitan area?
No. Garfield County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Garfield County?
9 ZIP Code Tabulation Areas have land in Garfield 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 Garfield 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 Garfield County?
The land measurement converts to approximately 2,992,998 acres. Including water, total area is approximately 3,103,421 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.