Benton County is a county in the south-central portion of the U.S. state of Washington. As of the 2020 census, its population was 206,873. The county seat is Prosser, and its most populous city is Kennewick. The Columbia River demarcates the county's north, south, and east boundaries.

The Hanford Reach National Monument is a national monument in the U.S. state of Washington. It was created in 2000, mostly from the former security buffer surrounding the Hanford Nuclear Reservation. The area has been untouched by development or agriculture since 1943. For this reason, it is considered an involuntary park.