South Dakota (USA) is 2.1 times larger than Portugal.
Area: 92,145 km2 Wikipedia
Population: 10,459,806 (2,013) World Bank
Continental Portugal or Mainland Portugal is the part of the territory of Portugal located in the Iberian Peninsula and so in Continental Europe. Continental Portugal is also commonly referred to - by the Portuguese - simply as the Continent. Wikipedia
South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux Native American tribes. South Dakota is the 17th most extensive, but the 5th least populous and the 5th least densely populated of the 50 United States. Wikipedia