Question: What county contains the city of Clayton, in the state where Riverfront Parkway is located?

full_context: Document 1: San Antonio River Walk: The River Walk is a successful special - case pedestrian street, one level down from the automobile street. The River Walk winds and loops under bridges as two parallel sidewalks lined with restaurants and shops, connecting the major tourist draws from the Shops at Rivercenter, to the Arneson River Theatre, to Marriage Island, to La Villita, to HemisFair Park, to the Tower Life Building, to the San Antonio Museum of Art, to the Pearl and the city's five Spanish colonial missions, which have been named a World Heritage Site, including the Alamo. During the annual springtime Fiesta San Antonio, the River Parade features flowery floats that float down the river.
Document 2: Detroit: The Detroit International Riverfront includes a partially completed three-and-one-half mile riverfront promenade with a combination of parks, residential buildings, and commercial areas. It extends from Hart Plaza to the MacArthur Bridge accessing Belle Isle Park (the largest island park in a U.S. city). The riverfront includes Tri-Centennial State Park and Harbor, Michigan's first urban state park. The second phase is a two-mile (3 km) extension from Hart Plaza to the Ambassador Bridge for a total of five miles (8 km) of parkway from bridge to bridge. Civic planners envision that the pedestrian parks will stimulate residential redevelopment of riverfront properties condemned under eminent domain.
Document 3: Riverfront Parkway: Riverfront Parkway is located along the Mississippi River in the cities of Davenport and Bettendorf in the U.S. state of Iowa. The parkway is a bike and walking trail that extends for 11 miles (17.7 km) starting at Credit Island on the west passing through Davenport for 7.6 miles (12.2 km) before entering Bettendorf. It continues for another 3.4 miles (5.47 km) at its terminus on the east side of Bettendorf. On Credit Island the bike path circles the park for 2.62 miles (4.22 km). On its way east from Credit Island it passes through Veterans Memorial Park, which is being developed, Centennial Park, LeClaire Park, River Heritage Park that is being developed on the east side of downtown Davenport, and Lindsay Park. In Bettendorf it passes through Leach Park. There are plans to connect the park to the Duck Creek Parkway and Sunderbruch Park in the future. There are public art installations along the parkway at Credit Island, Lindsay Park and Leach Park.
Document 4: Clayton Township, Perry County, Ohio: Clayton Township is one of the fourteen townships of Perry County, Ohio, United States. The 2000 census found 1,432 people in the township.
Document 5: Clayton, Missouri: Clayton is a city in and the county seat of St. Louis County, Missouri, United States, and borders the city of St. Louis. The population was 15,939 at the 2010 census. The city was organized in 1877 and is named after Ralph Clayton, who donated the land for the courthouse. The city is known for its multiple skyscrapers in its business district.
Document 6: Great River Road: The Great River Road is a collection of state and local roads that follow the course of the Mississippi River through ten states of the United States. They are Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi and Louisiana. It formerly extended north into Canada, serving the provinces of Ontario and Manitoba.
Document 7: Dow City, Iowa: Dow City is a city in Crawford County, Iowa, United States, along the Boyer River. The population was 510 at the 2010 census.
Document 8: Charles River Reservation Parkways: The Charles River Reservation Parkways are parkways that run along either side of the Charles River in eastern Massachusetts. The roads are contained within the Charles River Reservation and the Upper Charles River Reservation, and fall within a number of communities in the greater Boston metropolitan area. The Charles River parks extend from the Charles River Dam, where the Charles empties into Boston Harbor, to Riverdale Park in the West Roxbury neighborhood of Boston. Most of the roadways within the parks are listed on the National Register of Historic Places as a unit, although Storrow Drive and Memorial Drive are listed as part of the Charles River Basin Historic District.
Document 9: Detroit: Campus Martius, a reconfiguration of downtown's main intersection as a new park was opened in 2004. The park has been cited as one of the best public spaces in the United States. The city's riverfront has been the focus of redevelopment, following successful examples of other older industrial cities. In 2001, the first portion of the International Riverfront was completed as a part of the city's 300th anniversary celebration, with miles of parks and associated landscaping completed in succeeding years. In 2011, the Port Authority Passenger Terminal opened with the river walk connecting Hart Plaza to the Renaissance Center.
Document 10: Everly, Iowa: Everly is a city in Clay County, Iowa, United States. The population was 603 in the 2010 census, a decline from 647 in the 2000 census. The Ocheyedan River flows to the south and west of the city.
Document 11: Summit Township, Clay County, Iowa: Summit Township is a township in Clay County, Iowa, USA. As of the 2000 census, its population was 452. Spencer Municipal Airport is located in the township.
Document 12: Duck Creek (Quad Cities): Duck Creek is a minor tributary of the Mississippi River in the United States. The creek runs through Scott County, Iowa, and the cities of Davenport, Bettendorf, and Riverdale.
Document 13: Clayton, Iowa: Clayton is a city in Clayton County, Iowa, United States. The population was 43 at the 2010 census, down from 55 at the 2000 census. Clayton is located directly on the Mississippi River and is only accessible by a very steep road. Many people have summer homes in Clayton due to its proximity to the Mississippi River.
Document 14: Clayton Township, Adams County, Illinois: Clayton Township is one of twenty-two townships in Adams County, Illinois, United States. As of the 2010 census, its population was 1,027 and it contained 465 housing units.
Document 15: Clay City Township, Clay County, Illinois: Clay City Township is one of twelve townships in Clay County, Illinois, USA. As of the 2010 census, its population was 1,287 and it contained 649 housing units.
ground_truth: Clayton County
sub_queries: Which state is Riverfront Parkway located? Answer: Iowa
Clayton, Iowa >> located in the administrative territorial entity Answer: Clayton County