Rupert is the county seat and largest city of Minidoka County, Idaho, United States. It is part of the Burley Micropolitan Statistical Area. The population was 5,554 at the 2010 census.Rupert, founded in 1906, sprung up after the announcement of the Minidoka Reclamation Project, which provided irrigation and electricity following the completion of the Minidoka Dam in 1906. Electricity was plentiful after the building of the dam and led to Rupert being one of the first cities in the world to have its streets lighted by electricity.