Boise () is the
capital and most populous
city of the
U.S. state of
Idaho, as well as the
county seat of
Ada County. Located on the
Boise River in
southwestern Idaho, the population of Boise at the
2010 Census was 205,671, the
99th largest in the nation. Its estimated population in 2013 was 214,237. The
Boise-Nampa metropolitan area, also known as the Treasure Valley, includes five
counties with a combined population of 664,422, the most populous
metropolitan area in Idaho. It contains the state's three largest cities; Boise,
Nampa, and
Meridian. Boise is the third most populous metropolitan area in the United States'
Pacific Northwest region, behind
Seattle and
Portland.