Rupert is the county seat and largest city of Minidoka County, Idaho. It is part of the Burley Micropolitan Statistical Area. The population was 6,082 at the 2020 census, up from 5,554 in 2010.Rupert, founded in 1906, sprang up after the announcement of the Minidoka Reclamation Project, which provided irrigation and electricity following the completion of the Minidoka Dam on the Snake River in 1906.