Bellevue is a city in Blaine County in the central part of the U.S. state of Idaho. The population was 2,287 at the 2010 census, up from 1,876 i…Bellevue is a city in Blaine County in the central part of the U.S. state of Idaho. The population was 2,287 at the 2010 census, up from 1,876 in 2000. It is located in the Wood River Valley, about 18 miles south of the resort area of Ketchum and Sun Valley. The city of Hailey and the Friedman Memorial Airport are a few miles north of Bellevue. The Big Wood River flows near downtown.