Idaho Counties
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Idaho Counties

There are forty-four Counties in Idaho. When Idaho became a territory in March, 1863, there were four Counties in existence: Boise, Idaho, Nez Perce and Shoshone. By the time Idaho became a state, there were 15 counties. The rest of the 44 Counties came into existence during the 30 years after Idaho became a state. Two of the former counties disappeared during this time. Alturas, which was created in 1864, was later divided into the many counties now found in central Idaho. Logan County was only in existence for six years, from 1889 to 1895. It was combined with Alturas to form Blaine County and Lincoln County, which was formed just two weeks after Logan lost its identity.

Idaho County, Idaho

Idaho County Education, Geography, and HistoryIdaho County, Idaho Courthouse

Idaho County is a county located in the state of Idaho. Based on the 2010 census, the population was 16,267. The county was created  February 4, 1864. The county seat is Grangeville. Idaho county is named for a steamer called Idaho that was launched on the Columbia River in 1860.    

Idaho County is one of seven counties in the United States that has the same name as the state in which it lies. The other six are Arkansas, Hawaii, Iowa, New York, Oklahoma, and Utah.

Etymology - Origin of Idaho County Name

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.


County QuickFacts: CensusBureau Quick Facts

Idaho County History

Established February 4, 1864 by the First Idaho Territorial Legislature with its county seat at Florence. In 1861 it had been established as the third county of the Washington Territory. Named for the Steamer Idaho that was launched June 9, 1860 on the Columbia River and served miners during the gold rush in north Idaho. In 1875 Mount Idaho was named the county seat, in 1902 the county seat was moved to Grangeville following a 10-year struggle between Grangeville and Mount Idaho. Idaho County was originally founded as a region of Washington Territory in 1861. The county was reorganized by the Idaho Territorial Legislature on February 4, 1864. In this context, the name of the county predates both the Idaho Territory and the State of Idaho. Previous county seats of the area were Florence (1864-75) and Mount Idaho (1875-1902).

Geography: Land and Water

As reported by the Census Bureau, the county has a total area of 8,503 square miles (22,020 km2), of which 8,477 square miles (21,960 km2) is land and 26 square miles (67 km2) (0.3%) is water.

 Idaho county is located in north Idaho. The county is the largest county by area in Idaho.

Neighboring Counties

Bordering counties are as follows:

  • North: Clearwater County
  • Northeast: Missoula County, Mont.; Ravalli County, Mont.
  • Southeast: Lemhi County
  • South: Valley County
  • Southwest: Adams County
  • West: Wallowa County, Ore.
  • Northwest: Nez Perce County; Lewis County


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