List of Counties in Idaho - Alphabetical List

Alphabetical List

County	FIPS code	County seat	Established	Origin	Etymology	Population	Area
Ada County	001	Boise	1864	Boise County	Ada Riggs, daughter of H. C. Riggs, a member of the Idaho Territorial Legislature.	7005392365000000000392,365	70031055000000000001,055 sq mi (70032732000000000002,732 km2)
Adams County	003	Council	1911	Washington County	John Adams, second President of the United States .	70033976000000000003,976	70031365000000000001,365 sq mi (70033535000000000003,535 km2)
Bannock County	005	Pocatello	1893	Bingham County	Bannock Native American tribe.	700482839000000000082,839	70031113000000000001,113 sq mi (70032883000000000002,883 km2)
Bear Lake County	007	Paris	1893	Oneida County	Bear Lake on the Utah/Idaho border.	70035986000000000005,986	7002971000000000000971 sq mi (70032515000000000002,515 km2)
Benewah County	009	St. Maries	1915	Kootenai County	Benewah, chief of the Coeur d'Alene Tribe	70039285000000000009,285	7002776000000000000776 sq mi (70032010000000000002,010 km2)
Bingham County	011	Blackfoot	1885	Oneida County	Henry H. Bingham, a general in the American Civil War and a U.S. Congressman from Pennsylvania.	700445607000000000045,607	70032095000000000002,095 sq mi (70035426000000000005,426 km2)
Blaine County	013	Hailey	1895	Alturas County	James G. Blaine, United States Secretary of State .	700421376000000000021,376	70032645000000000002,645 sq mi (70036851000000000006,851 km2)
Boise County	015	Idaho City	1864	Original county	Boise River	70037028000000000007,028	70031902000000000001,902 sq mi (70034926000000000004,926 km2)
Bonner County	017	Sandpoint	1907	Kootenai County	Edwin L. Bonner, originator of a 1864 ferry service on the Kootenai River.	700440877000000000040,877	70031738000000000001,738 sq mi (70034501000000000004,501 km2)
Bonneville County	019	Idaho Falls	1911	Bingham County	Benjamin Bonneville, a French-born explorer of the West.	7005104234000000000104,234	70031869000000000001,869 sq mi (70034841000000000004,841 km2)
Boundary County	021	Bonners Ferry	1915	Bonner	Borders Canada on the north.	700410972000000000010,972	70031269000000000001,269 sq mi (70033287000000000003,287 km2)
Butte County	023	Arco	1917	Bingham, Blaine, and Jefferson counties	Buttes rising from the Snake River Plain.	70032891000000000002,891	70032233000000000002,233 sq mi (70035783000000000005,783 km2)
Camas County	025	Fairfield	1917	Blaine County	Camassia, a plant species important as a food source among Native Americans and early settlers.	70031117000000000001,117	70031075000000000001,075 sq mi (70032784000000000002,784 km2)
Canyon County	027	Caldwell	1892	Ada County	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.	7005188923000000000188,923	7002590000000000000590 sq mi (70031528000000000001,528 km2)
Caribou County	029	Soda Springs	1919	Bannock County	Caribou Mountains	70036963000000000006,963	70031766000000000001,766 sq mi (70034574000000000004,574 km2)
Cassia County	031	Burley	1879	Owyhee County	Disputed, either Cassia Creek or a member of the Mormon Battalion, James John Cazier.	700422952000000000022,952	70032567000000000002,567 sq mi (70036648000000000006,648 km2)
Clark County	033	Dubois	1919	Fremont County	Sam K. Clark, early settler and a member of the Idaho Senate.	7002982000000000000982	70031765000000000001,765 sq mi (70034571000000000004,571 km2)
Clearwater County	035	Orofino	1911	Nez Perce County	Clearwater River	70038761000000000008,761	70032462000000000002,462 sq mi (70036377000000000006,377 km2)
Custer County	037	Challis	1881	Alturas and Lemhi counties	General Custer mine, named after George Armstrong Custer, United States Army general.	70034368000000000004,368	70034926000000000004,926 sq mi (700412758000000000012,758 km2)
Elmore County	039	Mountain Home	1889	Alturas County	Ida Elmore mines, locally noted for gold and silver production in the 1860s.	700427038000000000027,038	70033078000000000003,078 sq mi (70037972000000000007,972 km2)
Franklin County	041	Preston	1913	Oneida County	Franklin D. Richards, early LDS Church apostle.	700412786000000000012,786	7002666000000000000666 sq mi (70031725000000000001,725 km2)
Fremont County	043	Saint Anthony	1893	Bingham County	John C. Frémont, an explorer of the West.	700413242000000000013,242	70031867000000000001,867 sq mi (70034836000000000004,836 km2)
Gem County	045	Emmett	1915	Boise and Canyon counties	State nickname of "Gem State."	700416719000000000016,719	7002563000000000000563 sq mi (70031458000000000001,458 km2)
Gooding County	047	Gooding	1913	Lincoln County	Frank R. Gooding, seventh Governor of Idaho, U.S. Senator .	700415464000000000015,464	7002731000000000000731 sq mi (70031893000000000001,893 km2)
Idaho County	049	Grangeville	1864	Original county	Columbia River steamship Idaho launched in 1860. Name predates both Idaho Territory and the State of Idaho.	700416267000000000016,267	70038485000000000008,485 sq mi (700421976000000000021,976 km2)
Jefferson County	051	Rigby	1913	Fremont County	Thomas Jefferson, third President of the United States .	700426140000000000026,140	70031095000000000001,095 sq mi (70032836000000000002,836 km2)
Jerome County	053	Jerome	1919	Gooding and Lincoln counties	Disputed, either North Side Irrigation Project developer Jerome Hill, his son-in-law Jerome Kuhn, or his grandson Jerome Kuhn, Jr.	700422374000000000022,374	7002600000000000000600 sq mi (70031554000000000001,554 km2)
Kootenai County	055	Coeur d'Alene	1864	Nez Perce County	Kootenai Native American tribe.	7005138494000000000138,494	70031245000000000001,245 sq mi (70033225000000000003,225 km2)
Latah County	057	Moscow	1888	Nez Perce County	Latah Creek, Nez Perce for "the place of pine trees and sestle."	700437244000000000037,244	70031077000000000001,077 sq mi (70032789000000000002,789 km2)
Lemhi County	059	Salmon	1869	Idaho County	Limhi, king of the Nephites according to the Book of Mormon.	70037936000000000007,936	70034564000000000004,564 sq mi (700411821000000000011,821 km2)
Lewis County	061	Nezperce	1911	Nez Perce County	Meriwether Lewis, a leader of the Lewis and Clark Expedition.	70033821000000000003,821	7002479000000000000479 sq mi (70031241000000000001,241 km2)
Lincoln County	063	Shoshone	1895	Logan County	Abraham Lincoln, sixteenth President of the United States . Idaho Territory was founded under Lincoln's administration.	70035208000000000005,208	70031206000000000001,206 sq mi (70033124000000000003,124 km2)
Madison County	065	Rexburg	1913	Fremont County	James Madison, fourth President of the United States .	700437536000000000037,536	7002472000000000000472 sq mi (70031222000000000001,222 km2)
Minidoka County	067	Rupert	1913	Lincoln County	Disputed Native American origin, either Lakota for "a fountain or spring of water" or Shoshoni for "broad expanse."	700420069000000000020,069	7002760000000000000760 sq mi (70031968000000000001,968 km2)
Nez Perce County	069	Lewiston	1864	Original county	The Nez Perce, a Native American tribe.	700439265000000000039,265	7002849000000000000849 sq mi (70032199000000000002,199 km2)
Oneida County	071	Malad City	1864	Original County	Oneida Lake in New York state, where many early settlers were from.	70034286000000000004,286	70031200000000000001,200 sq mi (70033108000000000003,108 km2)
Owyhee County	073	Murphy	1863	Original county	Corruption of Hawaii. Hawaiian fur trappers explored the area in 1819 and 1820.	700411526000000000011,526	70037678000000000007,678 sq mi (700419886000000000019,886 km2)
Payette County	075	Payette	1917	Canyon County	Francois Payette, Canadian-born fur trader and early settler.	700422623000000000022,623	7002408000000000000408 sq mi (70031057000000000001,057 km2)
Power County	077	American Falls	1913	Bingham, Blaine, and Oneida counties	The American Falls Power Plant	70037817000000000007,817	70031406000000000001,406 sq mi (70033642000000000003,642 km2)
Shoshone County	079	Wallace	1864	Original county	Shoshone Native American tribe.	700412765000000000012,765	70032634000000000002,634 sq mi (70036822000000000006,822 km2)
Teton County	081	Driggs	1915	Bingham, Fremont, and Madison counties	Teton Range and valley.	700410170000000000010,170	7002450000000000000450 sq mi (70031165000000000001,165 km2)
Twin Falls County	083	Twin Falls	1907	Cassia County	Twin Falls waterfall on the Snake River.	700477230000000000077,230	70031925000000000001,925 sq mi (70034986000000000004,986 km2)
Valley County	085	Cascade	1917	Boise and Idaho counties	Long Valley located in the county.	70037651000000000007,651	70033733000000000003,733 sq mi (70039668000000000009,668 km2)
Washington County	087	Weiser	1879	Ada County	George Washington, first President of the United States .	700410198000000000010,198	70031456000000000001,456 sq mi (70033771000000000003,771 km2)