Oneida County is a county located in the U.S. state of Idaho. As of the 2010 Census the county had a population of 4,286. The county seat and largest city is Malad City. Most of the county's population lives in Malad City and the surrounding Malad Valley.HistoryThe county is named for Oneida Lake, New York, the area from which most of the early settlers had emigrated.Oneida County was organized on January 22, 1864 with its county seat established at Soda Springs in present-day Caribou County. The county seat was moved to Malad City in 1866 because of its population growth and location on the freight road and stagecoach line between Corinne, Utah, and the mines in Butte, Montana.Early in its lengthy history, Oneida County had the distinction of being Idaho's largest county by both area and population. Its initial size was 32,708 mi2 making it the third largest of the 17 counties created by the first legislature of Idaho Territory in 1863 and early 1864. When the US Congress created Montana Territory on May 26, 1864, it also transferred a portion of Oneida County over to Dakota Territory. Even with the loss of territory, the act left Oneida County as Idaho's largest remaining Idaho county at 20,621 mi2. Alturas County exchanged territory with Boise County in 1866 to increase its land area above that of Oneida County. Oneida County lost significant territory to Wyoming Territory in 1868, to the creation of Bear Lake County in 1875, and to the creation of Cassia County in 1879. Minor adjustments to boundaries occurred in 1871, 1875, and 1877. Creation of Bingham County in 1885 left Oneida County with only 2,633 mi2, while creation of Franklin and Power Counties further reduced the county's area to 1,219 mi2 in 1913. Minor changes to boundaries occurred in 1917 and 1927 that gave Oneida County its present land area.
