Question: Shady Grove residents remaining within the state when visiting the Knoxville Raceway live in what county?

full_context: Document 1: South Grove Township, DeKalb County, Illinois: South Grove Township is one of nineteen townships in DeKalb County, Illinois, USA. As of the 2010 census, its population was 512 and it contained 209 housing units. South Grove Township was renamed from Vernon Township on November 20, 1850.
Document 2: Potomac Speedway: Potomac Speedway is a 3/8 mile clay oval raceway located in Budds Creek, Maryland, near Charlotte Hall. The raceway was first raced on in 1973. Races are typically held on Friday or Saturday nights. Regular events include Super Late Models, Limited Late Models, Street Stocks, and Hobby Stocks and 4 cylinders. The speedway also holds events for Modifieds, Crate Late Models, Strictly Stocks and Hornets. Potomac Speedway has a seating capacity of about 4,000 in the main grandstands and can hold an additional 1,000 in the pit area.
Document 3: Bristol Motor Speedway: Bristol Motor Speedway, formerly known as Bristol International Raceway and Bristol Raceway, is a NASCAR short track venue located in Bristol, Tennessee. Constructed in 1960, it held its first NASCAR race on July 30, 1961. Despite its short length, Bristol is among the most popular tracks on the NASCAR schedule because of its distinct features, which include extraordinarily steep banking, an all concrete surface, two pit roads, and stadium - like seating. It has also been named one of the loudest NASCAR tracks.
Document 4: Cornwall Motor Speedway: The Cornwall Motor Speedway is a 1/4 mile dirt track near the community of Cornwall, Ontario, Canada. It is located northwest of the city on Cornwall Centre Road. The track opened in 1970 and runs weekly racing on Sunday evenings.
Document 5: Balltown, Iowa: Balltown is a city in Dubuque County, Iowa, United States. It is part of the Dubuque, Iowa Metropolitan Statistical Area. The population was 68 at the 2010 census, down from 73 at the 2000 census. Balltown is home to Breitbach's Country Dining, Iowa's oldest restaurant and bar, which was founded in 1852 and twice rebuilt by the community, following its destruction by fire in 2007 and 2008.
Document 6: Shady Grove, Iowa: Shady Grove is a former townsite and unincorporated community in Buchanan County, Iowa, United States, between the cities of Brandon and Jesup. Settlement of Shady Grove began in 1857, but with the advent of rural migration, the population had dropped to 25 by the 1950s. New housing developments begun during the 1990s and 2000s, however, have caused the empty community to be reborn, causing controversy along the way.
Document 7: Shady Grove, Trousdale County, Tennessee: Shady Grove is an unincorporated community in Trousdale County, Tennessee, United States. Shady Grove is southeast of downtown Hartsville. As Hartsville and Trousdale County form a consolidated city-county government, Shady Grove is under the jurisdiction of Hartsville.
Document 8: Liberty Grove, Delta County, Texas: Liberty Grove is a ghost town in Delta County, Texas, United States. The community was settled by 1854, the year its school opened. The farming community included the school and a cemetery as of 1936. In 1966, the community had approximately 25 residents. The community's cemetery was relocated in 1989, and the community was subsequently abandoned and flooded by Cooper Lake. A campsite in Cooper Lake State Park bears the community's name.
Document 9: Tucson, Arizona: Tracks include Tucson Raceway Park and Rillito Downs. Tucson Raceway Park hosts NASCAR-sanctioned auto racing events and is one of only two asphalt short tracks in Arizona. Rillito Downs is an in-town destination on weekends in January and February each year. This historic track held the first organized quarter horse races in the world, and they are still racing there. The racetrack is threatened by development. The Moltacqua racetrack, was another historic horse racetrack located on what is now Sabino Canyon Road and Vactor Ranch Trail, but it no longer exists.
Document 10: Knoxville Raceway: Knoxville Raceway is a semi-banked 1/2 mile dirt oval raceway (zook clay) located at the Marion County Fairgrounds in Knoxville, Iowa, United States. Races at the "Sprint Car Capital of the World" are held on Saturday nights from April through September each year. Some special events may start as early as Wednesday and build up to Saturday. Regular events include 305 cubic inch, 360 cubic inch and 410 cubic inch sprint car racing. Each August, the Raceway holds the paramount sprint car event in the United States, the Knoxville Nationals. The track is governed by the 24-member fair board elected by Marion County residents.
Document 11: Beaver Dam Raceway: Beaver Dam Raceway is a one-third mile banked clay oval track located in Beaver Dam, Wisconsin, U.S.A.. The track holds weekly races over the Northern American summer months. It hosts an annual World of Outlaws sprint car races. The 2013 U.S. Dirt Legends Nationals event was held at the track.
Document 12: Shady Grove, McIntosh County, Oklahoma: Shady Grove is a census-designated place (CDP) in McIntosh County, Oklahoma, United States. The population was 199 at the 2010 census, a decrease of 14.4 percent from 229 in 2000.
Document 13: Exhibition game: Various auto racing organizations hold exhibition events; these events usually award no championship points to participants, but they do offer prize money to participants. The NASCAR Sprint Cup Series holds two exhibition events annually - the Sprint Unlimited, held at Daytona International Speedway at the start of the season, and the NASCAR Sprint All-Star Race, held at Charlotte Motor Speedway midway through the season. Both events carry a hefty purse of over USD $1,000,000. NASCAR has also held exhibition races at Suzuka Circuit and Twin Ring Motegi in Japan and Calder Park Thunderdome in Australia.
Document 14: Bear Grove Township, Guthrie County, Iowa: Bear Grove Township is one of seventeen townships in Guthrie County, Iowa, United States. It is located WSW of Guthrie Center just west of Sutcliff Woodland. As of the 2010 census, its population was 160.
Document 15: Island Grove Township, Gage County, Nebraska: Island Grove Township is one of twenty-four townships in Gage County, Nebraska, United States. The population was 103 at the 2000 census. A 2006 estimate placed the township's population at 103.
ground_truth: Buchanan County
sub_queries: In which state is Knoxville Raceway located? Answer: Iowa
Shady Grove, Iowa >> located in the administrative territorial entity Answer: Buchanan County