Cedar Rock State Park is a state park in Buchanan County, Iowa, United States, preserving the Frank Lloyd Wright-designed Lowell Walter Residence, also known as Cedar Rock. The Usonian- style house was constructed on a bank of the Wapsipinicon River near Quasqueton, Iowa, in 1950. Following Lowell Walter's death in 1981, the home was donated to the Iowa Department of Natural Resources and opened to the public.