Bonner-West Riverside is a census-designated place in Missoula County, Montana, United States, including the unincorporated communities of Bonner, Milltown, West Riverside, and Pinegrove. It is part of the Missoula metropolitan area. The population was 1,690 at the 2020 census. Bonner was named for Edward L. Bonner, president of the Missoula and Bitter Root Valley Railroad.