List of Idaho county name etymologies This is a list of Idaho county name etymologies . For an analysis of the county names , see Analysis of Idaho county namesakes . Ada County is named for Ada Riggs , the first pioneer child born in the area and the daughter of H. C. Riggs , a cofounder of Boise . Adams County is named for John Adams ( 1735-1826 ) , President of the United States from 1797 to 1801 . Bannock County is named for the Bannock Native American tribe . Bear Lake County is named for Bear Lake , which lies partly within the county and partly within Utah . Benewah County is named for a Coeur d'Alene Native American leader . Bingham County is named for Henry Harrison Bingham , a United States Representative from Pennsylvania and a friend of Idaho Territory Governor William M. Bunn . Blaine County is named for James Gillespie Blaine ( 1830-1893 ) , United States Secretary of State in 1881 and 1889 to 1892 and the 1884 Republican nominee for President of the United States . Boise County is named for the Boise River , which empties into the Snake River in western Canyon County . Boisé is French for wooded . Bonner County is named for Edwin L. Bonner , a pioneer ferry operator in the area . Bonneville County is named for Captain Benjamin Louis Eulalie de Bonneville , a French-born United States Army officer who explored the area in the 1830s . Boundary County is named for the fact that it borders Washington on the west , Montana on the east , and British Columbia , Canada , on the north . Butte County is named for the buttes that rise from the Snake River Plain , which served as landmarks to trappers and early explorers . Camas County is named for the camassia , a lily-like plant with an edible bulb , which is native to the area . Canyon County is named for a canyon in the area . Sources disagree whether the canyon is on the Boise River or the Snake River . Caribou County is named for the Caribou Mountains . Cassia County is named for Cassia Creek , which flows through the center of the county into the Raft River . Clark County is named for Sam K. Clark , an early member of the Idaho Legislature from the area . Clearwater County is named for the Clearwater River , which flows into the Snake River at Lewiston . Custer County is named for the General Custer mine , in turn named after General George Armstrong Custer . Elmore County is named for the Ida Elmore mines . Franklin County is named for Franklin , the first permanent town in the state , in turn named for Franklin Richards , an apostle of The Church of Jesus Christ of Latter-day Saints . Fremont County is named for John Charles Frémont ( 1813-1890 ) , a famous explorer and U.S. Senator . Gem County is named for the Idaho state nickname of Gem State . Gooding County is named for Frank Robert Gooding ( 1859-1928 ) , an Idaho governor and U.S. Senator in the early 20th Century . Idaho County is named for the steamer Idaho , which was launched on the Columbia River in 1860 . Originally a county in Washington Territory , the county 's name predates both the State of Idaho and Idaho Territory . Some sources say the name derives from ee-da-how , a word supposedly meaning the sun comes from the mountains in the Shoshone language . However , this explanation is now believed to be a hoax perpetrated by George M. Willing . Jefferson County is named for Thomas Jefferson ( 1743-1826 ) , President of the United States from 1801 to 1809 . Jerome County is named for either Jerome Hill , Jerome Kuhn or Jerome Kuhn , Jr. , three related local leaders important to the county . Kootenai County is named for the Kutenai Native American tribe . Latah County is named for Latah Creek , which in turn is named for a Nez Perce term for `` the place of pine trees and sestle. '' An earlier county was named Lah-Toh County . Lemhi County is named for Fort Lemhi , a local mission and fort of the Church of Jesus Christ of Latter-Day Saints , which in turn was named for King Lemhi , a figure in the Book of Mormon . Lewis County is named for Meriwether Lewis , a co-leader of the Lewis and Clark Expedition . Lincoln County is named for Abraham Lincoln ( 1809-1865 ) , President of the United States from 1861 to 1865 . Madison County is named for James Madison ( 1751-1836 ) , President of the United States from 1809 to 1817 . Minidoka County is named for a Dakota Sioux word for `` a fountain or spring of water '' Nez Perce County is named for the Nez Perce Native American tribe . Oneida County is named for the Oneida Lake area of New York from which many early settlers hailed . Owyhee County is named for the Kingdom of Hawaii . Hawaiian fur trappers had explored ( and had been mysteriously killed in ) the area around 1820 . Payette County is named for the Payette River , which , in turn , is named for explorer Francois Payette . Power County is named for the American Falls Power Plant . Shoshone County is named for the Shoshone Native American tribe . Teton County is named for the Teton Range . Twin Falls County is named for a waterfall on the Snake River . Valley County is named for the area 's Long Valley . Washington County is named for George Washington ( 1732-1799 ) , President of the United States from 1789 to 1797 . See also Idaho County ( United States ) List of Idaho counties Lists of U.S. county name etymologies Source Idaho Counties Categories : Idaho counties | U.S. county name etymologies 