The Root River Parkway is located in southwestern Milwaukee County and includes Whitnall Park, which is comprised of two significant sites – the Boerner Botanical Garden and Arboretum and Whitnall Golf Course.

Charles B. Whitnall included the Root River Parkway in his 1923 study of a county-wide parkway system. Alfred Boerner, a Milwaukee County landscape architect and Wisconsin native, was instrumental in designing the Parkway and its units, including the Boerner Botanical Gardens and Arboretum. George Hansen, Milwaukee County Park superintendent, designed the Whitnall Park Golf Course, which was implemented with work relief labor beginning in 1931. The Root River Parkway was profoundly influenced by federally-funded work relief efforts, with laborers the Civilian Conservation Corps (CCC), Works Progress Administration (WPA), Department of Outdoor Relief (DOR), National Youth Administration (NYA), and Civil Works Administration (CWA) performing work throughout the Parkway, Whitnall Park, the botanical garden and arboretum, and Whitnall Park Golf Course.

This segment of Parkway has been well maintained, and the Parkway remains historically intact. It is a strong example of parkway, park, and golf course design, and serves as a reminder of automobile culture and recreation, federal work relief efforts during the Depression era, and community development in early twentieth century Milwaukee County.