BOISE, city, capital of the State of Idaho, and county-seat of Ada co.; on the Boise river and the Oregon Short Line railroad; 45 miles S. W. of Idaho City. It occupies the site of a former trading post of the Hudson's Bay Company; is in an agricultural and a rich mining region; and is supplied with pure hot water from a flowing boiling well. It contains the State Capitol, erected in 1885-1887, a penitentiary, United States Assay Office, State Library, National banks, public library, excellent schools, hospitals, and other public buildings. Its industries include meat packing, stone quarrying, and manufactures of cigars, cement, etc. It is an important wool market. Pop. (1890) 2,311; (1910) 17,358; (1920) 21,393.