MI · GEOID 26131

Ontonagon County area

Ontonagon County, Michigan covers 3,740.4 square miles: 1,311 square miles of land and 2,429.5 square miles of water.

Official Census measurements2026 Gazetteer · retrieved September 27, 2026
Land area1,311 mi²
Water area2,429.5 mi²
Total area3,740.4 mi²
National land rank#455

County outline

Generalized outline of Ontonagon County, Michigan
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 Ontonagon County is located

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

Area breakdown

Land accounts for 35% of Ontonagon County’s measured area and water for 65%. Its combined area converts to 9,687.7 square kilometers or approximately 2,393,882 acres.

Green: land · blue: water

MeasurementSquare milesSquare kilometersAcres
Land1,310.9783,395.417839,025.9
Water2,429.4636,292.281,554,856.3
Total3,740.4419,687.6982,393,882.2

How Ontonagon County compares

By original Census land area, Ontonagon County ranks #3 of 83 in Michigan and #455 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.

Its land area is 2.309 times the Michigan county-equivalent median of 567.8 square miles. It accounts for 2.3% of the combined county land area in the state.

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

What stands out about Ontonagon County?

Ontonagon County has more land than 2,767 of the other 3,221 county equivalents in the dataset.

Land area compared with the typical county equivalent
Ontonagon County1,311 mi²
Michigan median567.8 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 Ontonagon County at #145 nationally by total area, 310 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 65%, compared with a national county-equivalent median of 1.2% — 63.8 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 Ontonagon County in the national ranking. They can be in different states and are not necessarily geographic neighbors.

Land rankCounty equivalentLand mi²Comparison
#454Glenn County, California1,313.9Compare
#455Ontonagon County, Michigan1,311This county
#456Schleicher County, Texas1,310.6Compare

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 46.835203, -89.276943. 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: 3,395,416,339 m²; AWATER: 6,292,279,170 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 many acres of land are in Ontonagon County?

The land measurement converts to approximately 839,026 acres. Including water, total area is approximately 2,393,882 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