List of counties in Idaho

There are 44 counties in the U.S. state of Idaho.

Alphabetical list

County
FIPS code[1] County seat[2] Established[2] Origin[3] License plate prefix[4] Meaning of name
[5]
Population (2020)[6] Area[2] Map
Ada County 001 Boise 1864 Boise County 1A Ada Riggs, daughter of H. C. Riggs, a member of the Idaho Territorial Legislature. 494,967 1,055 sq mi
(2,732 km2)
 
Adams County 003 Council 1911 Washington County 2A John Adams (1735-1826), second President of the United States (1797-1801). 4,379 1,365 sq mi
(3,535 km2)
 
Bannock County 005 Pocatello 1893 Bingham County 1B Bannock Native American tribe. 87,018 1,113 sq mi
(2,883 km2)
 
Bear Lake County 007 Paris 1875 Oneida County 2B Bear Lake on the Utah/Idaho border. 6,372 971 sq mi
(2,515 km2)
 
Benewah County 009 St. Maries 1915 Kootenai County 3B Ben'wah, chief of the Coeur d'Alene Tribe 9,530 776 sq mi
(2,010 km2)
 
Bingham County 011 Blackfoot 1885 Oneida County 4B Henry H. Bingham (1841-1912), a general in the American Civil War and a U.S. Congressman from Pennsylvania. 47,992 2,095 sq mi
(5,426 km2)
 
Blaine County 013 Hailey 1895 Alturas and Logan Counties 5B James G. Blaine (1830-1893), United States Secretary of State (1881, 1889-1892). 24,272 2,645 sq mi
(6,851 km2)
 
Boise County 015 Idaho City 1864 original county 6B Boise River 7,610 1,902 sq mi
(4,926 km2)
 
Bonner County 017 Sandpoint 1907 Kootenai County 7B Edwin L. Bonner, originator of an 1864 ferry service on the Kootenai River. 47,110 1,738 sq mi
(4,501 km2)
 
Bonneville County 019 Idaho Falls 1911 Bingham County 8B Benjamin Bonneville (1796-1878), a French-born explorer of the West. 123,964 1,869 sq mi
(4,841 km2)
 
Boundary County 021 Bonners Ferry 1915 Bonner County 9B Borders Canada on the north. 12,056 1,269 sq mi
(3,287 km2)
 
Butte County 023 Arco 1917 Bingham, Blaine, and Jefferson Counties 10B Buttes rising from the Snake River Plain. 2,574 2,233 sq mi
(5,783 km2)
 
Camas County 025 Fairfield 1917 Blaine County 1C Camassia, a plant species important as a food source among Native Americans and early settlers. 1,117 1,077 sq mi
(2,789 km2)
 
Canyon County 027 Caldwell 1892 Ada County 2C Disputed, either a canyon of the Boise River near Caldwell or a canyon of the Snake River which forms part of the county's boundary. 231,105 590 sq mi
(1,528 km2)
 
Caribou County 029 Soda Springs 1919 Bannock County 3C Caribou Mountains 7,027 1,766 sq mi
(4,574 km2)
 
Cassia County 031 Burley 1879 Owyhee County 4C Disputed, either Cassia Creek or a member of the Mormon Battalion, James John Cazier. 24,655 2,567 sq mi
(6,648 km2)
 
Clark County 033 Dubois 1919 Fremont County 5C Sam K. Clark, early settler and a member of the Idaho Senate. 790 1,765 sq mi
(4,571 km2)
 
Clearwater County 035 Orofino 1911 Nez Perce County 6C Clearwater River 8,734 2,462 sq mi
(6,377 km2)
 
Custer County 037 Challis 1881 Alturas and Lemhi Counties 7C General Custer mine, named after George Armstrong Custer (1839-1876), United States Army general. 4,275 4,926 sq mi
(12,758 km2)
 
Elmore County 039 Mountain Home 1889 Alturas County E Ida Elmore mines, locally noted for gold and silver production in the 1860s. 28,666 3,078 sq mi
(7,972 km2)
 
Franklin County 041 Preston 1913 Oneida County 1F Franklin D. Richards (1821-1899), early LDS Church apostle. 14,194 666 sq mi
(1,725 km2)
 
Fremont County 043 Saint Anthony 1893 Bingham County 2F John C. Frémont (1813-1890), an explorer of the West. 13,388 1,867 sq mi
(4,836 km2)
 
Gem County 045 Emmett 1915 Boise and Canyon Counties 1G State nickname of "Gem State." 19,123 563 sq mi
(1,458 km2)
 
Gooding County 047 Gooding 1913 Lincoln County 2G Frank R. Gooding (1859-1928), seventh Governor of Idaho (1905-1909), U.S. Senator (1921-1928). 15,598 731 sq mi
(1,893 km2)
 
Idaho County 049 Grangeville 1864 original county I Columbia River steamship Idaho launched in 1860. Name predates both Idaho Territory and the State of Idaho. 16,541 8,485 sq mi
(21,976 km2)
 
Jefferson County 051 Rigby 1913 Fremont County 1J Thomas Jefferson (1743-1826), third President of the United States (1801-1809). 30,891 1,095 sq mi
(2,836 km2)
 
Jerome County 053 Jerome 1919 Gooding and Lincoln Counties 2J Disputed, either North Side Irrigation Project developer Jerome Hill, his son-in-law Jerome Kuhn, or his grandson Jerome Kuhn, Jr. 24,237 600 sq mi
(1,554 km2)
 
Kootenai County 055 Coeur d'Alene 1864 Nez Perce County K Kootenai Native American tribe. 171,362 1,245 sq mi
(3,225 km2)
 
Latah County 057 Moscow 1888 Nez Perce County 1L Latah Creek, Nez Perce for "the place of pine trees and sestle." 39,517 1,077 sq mi
(2,789 km2)
 
Lemhi County 059 Salmon 1869 Idaho County 2L Limhi, king of the Nephites according to the Book of Mormon. 7,974 4,564 sq mi
(11,821 km2)
 
Lewis County 061 Nezperce 1911 Nez Perce County 3L Meriwether Lewis (1774-1809), a leader of the Lewis and Clark Expedition. 3,533 479 sq mi
(1,241 km2)
 
Lincoln County 063 Shoshone 1895 Blaine County 4L Abraham Lincoln (1809-1865), sixteenth President of the United States (1861-1865). Idaho Territory was founded under Lincoln's administration. 5,127 1,206 sq mi
(3,124 km2)
 
Madison County 065 Rexburg 1913 Fremont County 1M James Madison (1751-1836), fourth President of the United States (1809-1817). 52,913 472 sq mi
(1,222 km2)
 
Minidoka County 067 Rupert 1913 Lincoln County 2M Disputed Native American origin, either Lakota for "a fountain or spring of water" or Shoshoni for "broad expanse." 21,613 760 sq mi
(1,968 km2)
 
Nez Perce County 069 Lewiston 1864 original county N The Nez Perce, a Native American tribe. 42,090 849 sq mi
(2,199 km2)
 
Oneida County 071 Malad City 1864 original county 1O Oneida Lake in New York state, where many early settlers were from. 4,564 1,200 sq mi
(3,108 km2)
 
Owyhee County 073 Murphy 1863 original county 2O Alternate spelling of Hawaii. Hawaiian fur trappers explored the area in 1819 and 1820. 11,913 7,678 sq mi
(19,886 km2)
 
Payette County 075 Payette 1917 Canyon County 1P Francois Payette (1793-1844?), Canadian-born fur trader and early settler. 25,386 408 sq mi
(1,057 km2)
 
Power County 077 American Falls 1913 Bingham, Blaine, and Oneida Counties 2P The American Falls Power Plant 7,878 1,406 sq mi
(3,642 km2)
 
Shoshone County 079 Wallace 1864 original county S Shoshone Native American tribe. 13,169 2,634 sq mi
(6,822 km2)
 
Teton County 081 Driggs 1915 Bingham, Fremont, and Madison Counties 1T Teton Range in Wyoming. 11,630 450 sq mi
(1,165 km2)
 
Twin Falls County 083 Twin Falls 1907 Cassia County 2T Twin Falls waterfall on the Snake River. 90,046 1,925 sq mi
(4,986 km2)
 
Valley County 085 Cascade 1917 Boise and Idaho Counties V Long Valley located in the county. 11,746 3,733 sq mi
(9,668 km2)
 
Washington County 087 Weiser 1879 Ada County W George Washington (1732-1799), first President of the United States (1789-1797). 10,500 1,456 sq mi
(3,771 km2)
 

Old Idaho counties

  • Alturas County: A huge county in south-central Idaho that was formed in 1864, but split up in 1895.
  • Lah-Toh County, Idaho Territory: A county in northern Idaho that was formed in 1864, but it was ended a short time later in 1867.
  • Logan County: Formed by a partition of Alturas County in 1889, bit it was shortly ended in 1895.

References

  1. "EPA County FIPS Code Listing". EPA.gov. Retrieved 2008-02-23.
  2. 2.0 2.1 2.2 National Association of Counties. "NACo - Find a county". Archived from the original on 2007-10-24. Retrieved 2008-04-26.
  3. Hailey, John (1910). The History of Idaho. Press of Syms-York company. pp. 305–307. OCLC 5793481. Retrieved 2008-04-26.
  4. "County License Plate Designators List" (PDF). Idaho Transportation Department. Retrieved 2018-06-30.
  5. "List of Idaho Counties - Idaho.gov". State of Idaho. Archived from the original on 2008-07-05. Retrieved 2008-07-30.
  6. "Idaho QuickFacts". U.S. Census Bureau. Retrieved 2021-09-02. (2020 Census)