Grant County area

Grant County, Oregon covers 4,528.5 square miles: 4,527.8 square miles of land and 0.731 square miles of water. Its county seat is Canyon City. An estimated 7,075 people lived there in 2025.

Official Census measurements · GEOID 410232026 Gazetteer · retrieved September 27, 2026
Land area4,527.8 mi²
Water area0.731 mi²
Population (2025)7,075
People per mi²1.6

County outline

Generalized outline of Grant County, Oregon
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 Grant County is located

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

Area breakdown

Land accounts for 100% of Grant County’s measured area and water for 0%. Its combined area converts to 11,728.8 square kilometers or approximately 2,898,255 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land4,527.79211,726.9272,897,786.9
Water0.7311.893467.8
Total4,528.52311,728.8212,898,254.7

How Grant County compares

By original Census land area, Grant County ranks #7 of 36 in Oregon and #100 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 2.479 times the Oregon county-equivalent median of 1,826.2 square miles. It accounts for 4.7% of the combined county land area in the state.

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

Population and density of Grant County

The Census Bureau estimates that 7,075 people lived in Grant County on July 1, 2025. That ranks #2,726 of 3,222 county equivalents nationally and #33 of 36 in Oregon. Since the April 1, 2020 estimates base of 7,231, the population has declined by 156 (−2.2%), compared with +0.9% for Oregon as a whole.

With 4,527.8 square miles of land, that is 1.6 people per square mile (0.6 per km²), placing Grant County #3,100 nationally for density and #33 in Oregon. The median county equivalent has 47 people per square mile; the Oregon median is 25. Put another way, there are about 410 acres of land per resident.

Estimated population, 2020–2025 · line scaled to this county’s own range
July 1202020212022202320242025
Estimate7,2407,2937,2277,2287,1047,075
Change—+53−66+1−124−29

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 Grant County

9 incorporated places lie at least partly in Grant County. Together they are home to 4,239 people (59.9%); the other 2,836 (40.1%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is John Day city, with 1,634 residents in the county. The county seat, Canyon City town, has 644 residents.

Incorporated placePopulation 2025Since 2020Land mi²
John Day city1,634−2.3%2.26
Prairie City city819−2.6%0.992
Canyon City townCounty seat644−2.7%1.408
Mount Vernon city545−0.5%0.683
Long Creek city166−2.4%1.023
Seneca city160−3%0.795
Dayville town130−2.3%0.526
Monument city112−1.8%0.509
Granite city290%0.372

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

Metropolitan area

Grant 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

12 ZIP Code Tabulation Areas have land in Grant County; 11 of them have most of their land inside the county, and the others mainly cover neighboring areas.

978179782097825978459784897856978649786597869978739787797880

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 Grant County

Grant County shares a land border with 8 county equivalents. It has more land than 6 of them. The largest neighbor is Harney County (10,134.5 mi²) and the smallest is Wheeler County (1,716 mi²). Together with its neighbors, Grant County forms a block of 39,595.8 mi² of land, of which it holds 11.4%.

Map of Grant County and the 8 county equivalents that border it Harney County, Oregon: 10,134.5 mi² landBaker County, Oregon: 3,068 mi² landWheeler County, Oregon: 1,716 mi² landUmatilla County, Oregon: 3,215.5 mi² landMorrow County, Oregon: 2,030.5 mi² landCrook County, Oregon: 2,978.9 mi² landMalheur County, Oregon: 9,887.7 mi² landUnion County, Oregon: 2,036.9 mi² land
Grant 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. GrantCompare
Harney County10,134.52.2× largerCompare
Malheur County9,887.72.2× largerCompare
Umatilla County3,215.51.4× smallerCompare
Baker County3,0681.5× smallerCompare
Crook County2,978.91.5× smallerCompare
Union County2,036.92.2× smallerCompare
Morrow County2,030.52.2× smallerCompare
Wheeler County1,7162.6× smallerCompare

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

Grant County has more land than 2 of the 50 states. It is about 2.3 times the land area of Delaware (1,948.6 mi²), while Connecticut, the next larger state, has 1.1 times as much land (4,842.5 mi²). Oregon’s county land could hold about 21 areas the size of Grant County.

Land area: Grant County and the closest-sized states
Delaware1,948.6 mi²
Grant County4,527.8 mi²
Connecticut4,842.5 mi²

Another way to picture it: the same land area would fill a square about 67.3 miles (108.3 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 Grant County?

Grant County has more land than 3,122 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Grant County4,527.8 mi²
Oregon median1,826.2 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 Grant County at #107 nationally by total area, 7 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%, compared with a national county-equivalent median of 1.2% — 1.2 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 Grant County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#99Cibola County, New Mexico4,540Compare
#100Grant County, Oregon4,527.8This county
#101La Paz County, Arizona4,496.6Compare

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 44.496326, -119.014057. 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: 11,726,925,880 m²; AWATER: 1,893,807 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 Grant County?

Grant County, Oregon has 4,527.8 square miles (11,726.9 km²) of land and 0.731 square miles of water, for a total area of 4,528.5 square miles. It ranks #100 of 3,222 U.S. county equivalents by land area.

Is Grant County the largest county in Oregon?

No. Grant County ranks #7 of 36 in Oregon by land area. The largest is Harney County, with 10,134.5 square miles of land.

What counties border Grant County?

Grant County shares a land border with Harney County, Baker County, Wheeler County, Umatilla County, Morrow County, Crook County, Malheur County, and Union County.

What is the population of Grant County?

The Census Bureau estimates Grant County had 7,075 residents on July 1, 2025, ranking #2,726 of 3,222 county equivalents. That is 1.6 people per square mile of land.

What is the county seat of Grant County?

The county seat of Grant County is Canyon City.

What cities and towns are in Grant County?

Grant County has 9 incorporated places. The most populous five are John Day city, Prairie City city, Canyon City town, Mount Vernon city, and Long Creek city; 2,836 residents live outside any incorporated place.

Is Grant County part of a metropolitan area?

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

How many ZIP codes are in Grant County?

12 ZIP Code Tabulation Areas have land in Grant County, and 11 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.

How does Grant 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 Grant County?

The land measurement converts to approximately 2,897,787 acres. Including water, total area is approximately 2,898,255 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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