44 Counties — idaho
| County | Type | Population | Land area |
|---|
| ada | County | 300,904 | 1,055 sq mi |
| adams | County | 3,476 | 1,365 sq mi |
| bannock | County | 75,565 | 1,113 sq mi |
| bear lake | County | 6,411 | 971 sq mi |
| benewah | County | 9,171 | 776 sq mi |
| bingham | County | 41,735 | 2,095 sq mi |
| blaine | County | 18,991 | 2,645 sq mi |
| boise | County | 6,670 | 1,903 sq mi |
| bonner | County | 36,835 | 1,738 sq mi |
| bonneville | County | 82,522 | 1,869 sq mi |
| boundary | County | 9,871 | 1,269 sq mi |
| butte | County | 2,899 | 2,233 sq mi |
| camas | County | 991 | 1,075 sq mi |
| canyon | County | 131,441 | 590 sq mi |
| caribou | County | 7,304 | 1,766 sq mi |
| cassia | County | 21,416 | 2,567 sq mi |
| clark | County | 1,022 | 1,765 sq mi |
| clearwater | County | 8,930 | 2,462 sq mi |
| custer | County | 4,342 | 4,926 sq mi |
| elmore | County | 29,130 | 3,078 sq mi |
| franklin | County | 11,329 | 666 sq mi |
| fremont | County | 11,819 | 1,867 sq mi |
| gem | County | 15,181 | 563 sq mi |
| gooding | County | 14,155 | 731 sq mi |
| idaho | County | 15,511 | 8,485 sq mi |
| jefferson | County | 19,155 | 1,095 sq mi |
| jerome | County | 18,342 | 600 sq mi |
| kootenai | County | 108,685 | 1,245 sq mi |
| latah | County | 34,935 | 1,077 sq mi |
| lemhi | County | 7,806 | 4,564 sq mi |
| lewis | County | 3,747 | 479 sq mi |
| lincoln | County | 4,044 | 1,206 sq mi |
| madison | County | 27,467 | 472 sq mi |
| minidoka | County | 20,174 | 760 sq mi |
| nez perce | County | 37,410 | 849 sq mi |
| oneida | County | 4,125 | 1,200 sq mi |
| owyhee | County | 10,644 | 7,678 sq mi |
| payette | County | 20,578 | 408 sq mi |
| power | County | 7,538 | 1,406 sq mi |
| shoshone | County | 13,771 | 2,634 sq mi |
| teton | County | 5,999 | 450 sq mi |
| twin falls | County | 64,284 | 1,925 sq mi |
| valley | County | 7,651 | 3,678 sq mi |
| washington | County | 9,977 | 1,456 sq mi |