West county atlas

Idaho county map

Explore all 44 counties. Select a county to see its map, or download a copy for your next project.

Boundary map 100%
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2025 U.S. Census boundaries. Zoom to reveal more names. Drag to pan when zoomed; use arrow keys, + and − with the map focused.

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SVG

SVG is editable vector artwork. PNG is a high-resolution image. PDF uses landscape Letter pages, with a separate key when needed.

Downloads contain the complete boundary map, independent of zoom. Crowded names use a numbered key. Numbered quiz maps use the county list / answer key (CSV). Boundary data (GeoJSON) · Reuse with source credit.

Roads, terrain & aerial imagery

Explore Idaho with a county boundary overlay. Choose a view to load the interactive map.

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Street names, terrain, or aerial photography with the county boundary in view.

Backgrounds load from OpenStreetMap or USGS only when selected. Imagery dates and detail vary by location.

Map scope: Use the boundary map for names and shapes, or the interactive background viewer for roads, terrain, and aerial imagery. County boundaries do not identify parcels or ZIP codes.

Idaho county geography overview

Idaho has 44 counties, which places it 32nd among the 50 state and District of Columbia maps in this atlas when ordered by number of county-level units. Their combined 82,645.4 square miles of land place the state 11th by mapped land area.

The average county-level area is 1,878 square miles, while the median is 1,316 square miles. The median is often the better description of a typical unit because one or two very large areas can pull the average upward. The five largest units together account for about 35% of the state’s mapped land area.

44county-level units
1,316 sq mimedian land area
8,477.5 sq milargest unit
1%share of mapped area that is water

Largest and smallest Idaho counties

Idaho County is the largest county-level unit by land area at 8,477.5 square miles. It represents about 10% of all mapped land in Idaho. At the other end of the range, Payette County has 406.9 square miles of land.

Largest by land area

  1. Idaho County8,477.5 sq mi
  2. Owyhee County7,668.2 sq mi
  3. Custer County4,922.2 sq mi
  4. Lemhi County4,563.7 sq mi
  5. Valley County3,665.1 sq mi

Smallest by land area

  1. Payette County406.9 sq mi
  2. Teton County449.1 sq mi
  3. Madison County469.3 sq mi
  4. Lewis County478.8 sq mi
  5. Gem County559.8 sq mi

Rankings use land area rather than total area. This avoids making coastal or lake counties appear larger solely because their boundaries include extensive water.

Alphabetical list of Idaho counties

The table is alphabetical, so it works as a name and FIPS-code reference rather than an area ranking. Every identifier begins with the Idaho state FIPS prefix 16. Land and water figures are rounded to one decimal place.

44 county-level areas

Download county data / numbered map key (CSV)
No.NameFIPS codeLand areaWater area
1Ada County160011,052.3 sq mi8.5 sq mi
2Adams County160031,362.8 sq mi6.7 sq mi
3Bannock County160051,112.5 sq mi35.6 sq mi
4Bear Lake County16007975.7 sq mi73.9 sq mi
5Benewah County16009776.9 sq mi7.3 sq mi
6Bingham County160112,093.7 sq mi26.5 sq mi
7Blaine County160132,637.7 sq mi17.2 sq mi
8Boise County160151,899.4 sq mi7.4 sq mi
9Bonner County160171,733.2 sq mi184.9 sq mi
10Bonneville County160191,866 sq mi34.3 sq mi
11Boundary County160211,268.7 sq mi9.4 sq mi
12Butte County160232,236.5 sq mi2 sq mi
13Camas County160251,074.2 sq mi4.5 sq mi
14Canyon County16027587 sq mi16.6 sq mi
15Caribou County160291,764.2 sq mi34.4 sq mi
16Cassia County160312,565.6 sq mi15.1 sq mi
17Clark County160331,763.1 sq mi1 sq mi
18Clearwater County160352,457.3 sq mi30.7 sq mi
19Custer County160374,922.2 sq mi16.4 sq mi
20Elmore County160393,075.1 sq mi26.4 sq mi
21Franklin County16041663 sq mi4.7 sq mi
22Fremont County160431,864 sq mi32.2 sq mi
23Gem County16045559.8 sq mi4.8 sq mi
24Gooding County16047729.3 sq mi4.8 sq mi
25Idaho County160498,477.5 sq mi26.1 sq mi
26Jefferson County160511,093.7 sq mi12 sq mi
27Jerome County16053597.5 sq mi5 sq mi
28Kootenai County160551,237.8 sq mi71.2 sq mi
29Latah County160571,075.9 sq mi0.9 sq mi
30Lemhi County160594,563.7 sq mi5.4 sq mi
31Lewis County16061478.8 sq mi0.9 sq mi
32Lincoln County160631,201.4 sq mi4.5 sq mi
33Madison County16065469.3 sq mi4.1 sq mi
34Minidoka County16067757.2 sq mi5.1 sq mi
35Nez Perce County16069848.3 sq mi8.2 sq mi
36Oneida County160711,199 sq mi1.5 sq mi
37Owyhee County160737,668.2 sq mi28.6 sq mi
38Payette County16075406.9 sq mi3.4 sq mi
39Power County160771,403.8 sq mi38.3 sq mi
40Shoshone County160792,637.4 sq mi5.4 sq mi
41Teton County16081449.1 sq mi1.1 sq mi
42Twin Falls County160831,921.7 sq mi7 sq mi
43Valley County160853,665.1 sq mi68.4 sq mi
44Washington County160871,452.9 sq mi20.5 sq mi

How to read and use this map

County lines are administrative boundaries, not postal routes. A mailing address can use a city name associated with a neighboring area, and ZIP codes can cross county lines. When you need to identify a county for an address, confirm it with an official geocoder or local government source.

For classroom or planning use, download a PDF from the controls above. Labelled exports use numbered callouts for crowded areas; numbered quiz maps match the alphabetical county list. SVG files keep the boundary lines sharp at larger paper sizes.

Frequently asked questions

How many counties are in Idaho?

Idaho has 44 counties in the U.S. Census Bureau’s 2025 cartographic boundary file.

Can I print this Idaho county map?

Yes. Choose Download / print and select PDF for a landscape Letter page, PNG for an image, or SVG for editable vector artwork. Because the map is SVG, its boundary lines stay sharp when scaled.

What is the largest county in Idaho?

Idaho County is the largest by land area in this dataset at 8,477.5 square miles. This is an area ranking, not a population ranking.

What is the smallest county in Idaho?

Payette County is the smallest by land area in this dataset at 406.9 square miles.

Are these legal survey boundaries?

No. This is a generalized reference map. Property, parcel, election, and legal boundary questions should be checked with the relevant state or local agency.

Map source

U.S. Census Bureau, 2025 Cartographic Boundary File, Counties, 1:5,000,000. Land and water area fields are supplied in the same file and converted from square meters to square miles. Accessed September 27, 2026.