Richland is a city in Benton County, Washington, United States. It is located in southeastern Washington at the confluence of the Yakima …Richland is a city in Benton County, Washington, United States. It is located in southeastern Washington at the confluence of the Yakima and the Columbia Rivers. As of the 2020 census, the city's population was 60,560. Along with the nearby cities of Pasco and Kennewick, Richland is one of the Tri-Cities, and is home to the Hanford nuclear site.