Oregon (USA) is 27% larger than South Dakota (USA).
Oregon is a state in the Pacific Northwest of the United States. It is bordered on its west by the Pacific Ocean, north by Washington, south by California, east by Idaho, and southeast by Nevada. The Columbia River delineates much of Oregon's northern boundary, the Snake River largely its eastern. 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