Badlands National Park is 92% larger than Palau.
Area: 459 km2 World Factbook
Population: 21,186 (July 2014) World Factbook
Palau, officially the Republic of Palau, is an island country located in the western Pacific Ocean. It is geographically part of the larger island group of Micronesia. The country's population of around 21,000 is spread across 250 islands forming the western chain of the Caroline Islands. Wikipedia
Area: 882 km2 calculated
Badlands National Park is a national park in southwestern South Dakota that protects 242,756 acres of sharply eroded buttes, pinnacles, and spires blended with the largest undisturbed mixed grass prairie in the United States. The park is managed by the National Park Service. Wikipedia