Bermejo is a city in Bolivia, south of the Tariquía Flora and Fauna National Reserve. It is in a broad, open valley of the Cordillera Central range t…Bermejo is a city in Bolivia, south of the Tariquía Flora and Fauna National Reserve. It is in a broad, open valley of the Cordillera Central range that extends southward into Argentina, and is on the Bermejo River, locally the border between Bolivia and Argentina.