According to census.gov, Ada County, Idaho, has the most population at 373,406 people in 2007.
The most populated county in Idaho is Ada County, with a population of more than 390,000.
Ada County is the most populous county in Idaho, with an estimated 392,365 people.
As of the 2000 Census, the population of Idaho County Idaho is, 15,511.
As of the 2000 Census, the population of Bonner County Idaho is 36,835.
As of the 2000 Census the population of Bannock County, Idaho is 75,565.
As of the 2000 Census, the population of Bingham County Idaho is 41,735.
As of the 2000 Census, the population of Boundary County Idaho is, 9,871.
As of the 2000 Census, the population of Butte County Idaho is, 2,899.
As of the 2000 Census, the population of Camas County Idaho is, 991.
As of the 2000 Census, the population of Cassia County Idaho is, 21,416.
As of the 2000 Census, the population of Franklin County Idaho is, 11,329.
As of the 2000 Census, the population of Gen County Idaho is, 15,181.