Washington County, Idaho
Washington County Courthouse in Weiser
Location within the U.S. state of Idaho
Idaho's location within the U.S.
|Founded||February 20, 1879|
|Named for||George Washington|
|• Total||1,474 sq mi (3,820 km2)|
|• Land||1,453 sq mi (3,760 km2)|
|• Water||21 sq mi (50 km2) 1.4%%|
| • Estimate |
|• Density||7.0/sq mi (2.7/km2)|
|Time zone||UTC−7 (Mountain)|
|• Summer (DST)||UTC−6 (MDT)|
Washington County is a county in the U.S. state of Idaho. As of the 2010 census, the population was 10,198. The county seat and largest city is Weiser. It has over half of the county's population. The county was founded in 1879 when Idaho was a territory and named after George Washington, the first President of the United States (1789–1797).