Greenwater is a census-designated place (CDP) in the northwest United States in Pierce County, Washington. Southeast of Seattle, the population was 67 at the 2010 census, down from 91 in 2000. At the 2020 census, the population was 95.

State Route 410 is a 107.44-mile (172.91 km) long state highway that traverses Pierce, King, and Yakima counties in the US state of Washington. It begins at an interchange with SR 167 in Sumner and travels southeast across the Cascade Range to a junction with U.S. Route 12 (US 12) in Naches. While the western part of SR 410 is a freeway that serves built-up, urban areas, the remainder of the route is a surface road that traverses mostly rural areas as it passes through the mountains.