Idaho Counties by Land Area
Want to know about the largest to smallest counties in Idaho, USA in terms of total land area? Check this resource Idaho counties by land area to discover all the details regarding county map (boundary), and nearby counties. On the other hand, check Idaho counties by population and Idaho cities by population to know more about city and county based demographic details.
What is the largest county in Idaho by land area?
Idaho County is the largest county in Idaho spanning 8477.5 square miles, with an additional 26.07 square miles of water area. Following Idaho County, Owyhee County ranks as the second largest in terms of land area, covering 7668.2 square miles, while Custer County secures the position as the third largest county in Idaho.
What is the smallest county by land area in Idaho?
Payette County is the smallest in Idaho by total land area, covers about 406.89 square miles.
What is the largest county by population in Idaho?
Ada County in Idaho, USA, stands as the most populous county having 494,967 residents as per the 2022 census data.
What is the smallest county by population in Idaho?
Clark County is the smallest in Idaho by total population, having 790 residents as per the 2022 census data.
| Rank | County in Idaho | Land Area square miles | Water Area square miles | Total Area square miles |
|---|---|---|---|---|
| 1 | Idaho County | 8,478 | 26 | 8,504 |
| 2 | Owyhee County | 7,668 | 29 | 7,697 |
| 3 | Custer County | 4,922 | 16 | 4,939 |
| 4 | Lemhi County | 4,564 | 5 | 4,569 |
| 5 | Valley County | 3,665 | 68 | 3,734 |
| 6 | Elmore County | 3,075 | 26 | 3,101 |
| 7 | Blaine County | 2,638 | 17 | 2,655 |
| 8 | Shoshone County | 2,637 | 5 | 2,643 |
| 9 | Cassia County | 2,566 | 15 | 2,581 |
| 10 | Clearwater County | 2,457 | 31 | 2,488 |
| 11 | Butte County | 2,236 | 2 | 2,239 |
| 12 | Bingham County | 2,094 | 26 | 2,120 |
| 13 | Twin Falls County | 1,922 | 7 | 1,929 |
| 14 | Boise County | 1,900 | 7 | 1,907 |
| 15 | Bonneville County | 1,866 | 34 | 1,900 |
| 16 | Fremont County | 1,864 | 32 | 1,896 |
| 17 | Caribou County | 1,764 | 34 | 1,799 |
| 18 | Clark County | 1,763 | 1 | 1,764 |
| 19 | Bonner County | 1,733 | 185 | 1,918 |
| 20 | Washington County | 1,453 | 21 | 1,473 |
| 21 | Power County | 1,404 | 38 | 1,442 |
| 22 | Adams County | 1,363 | 7 | 1,370 |
| 23 | Boundary County | 1,269 | 9 | 1,278 |
| 24 | Kootenai County | 1,238 | 71 | 1,309 |
| 25 | Lincoln County | 1,201 | 4 | 1,206 |
| 26 | Oneida County | 1,199 | 2 | 1,200 |
| 27 | Bannock County | 1,112 | 36 | 1,148 |
| 28 | Jefferson County | 1,094 | 12 | 1,106 |
| 29 | Latah County | 1,076 | 1 | 1,077 |
| 30 | Camas County | 1,074 | 4 | 1,079 |
| 31 | Ada County | 1,052 | 9 | 1,061 |
| 32 | Bear Lake County | 976 | 74 | 1,050 |
| 33 | Nez Perce County | 848 | 8 | 857 |
| 34 | Benewah County | 777 | 7 | 784 |
| 35 | Minidoka County | 757 | 5 | 762 |
| 36 | Gooding County | 729 | 5 | 734 |
| 37 | Franklin County | 663 | 5 | 668 |
| 38 | Jerome County | 598 | 5 | 603 |
| 39 | Canyon County | 587 | 17 | 604 |
| 40 | Gem County | 560 | 5 | 565 |
| 41 | Lewis County | 479 | 1 | 480 |
| 42 | Madison County | 469 | 4 | 473 |
| 43 | Teton County | 449 | 1 | 450 |
| 44 | Payette County | 407 | 3 | 410 |