Rüegsau is a municipality in the district of Trachselwald in the Swiss canton of Bern.Rüegsau is located in the lower Emmental. It borders the Emme and then stretches north-east-ward. It contains the villages of Rüegsauschachen, Rüegsau, Rüegsbach and Rinderbach and several hamlets. The municipality has the approximate shape of ...