Rivergrove is a city in Clackamas County, Oregon, United States. A small portion of the city extends into nearby Washington County. Its name i…Rivergrove is a city in Clackamas County, Oregon, United States. A small portion of the city extends into nearby Washington County. Its name is a portmanteau of the Tualatin River, which forms its southern border, and Lake Grove, a community that is now part of Lake Oswego. Interstate 5 forms the western border, with Childs Road serving as the northern border for much of the city. The population was 545 at the 2020 census.