Question: What Illinois county contains the city that shares its name with the birthplace of Trevor Matthews?

full_context: Document 1: Trevor Matthews: Trevor Matthews (born July 24, 1982 in Ottawa, Ontario) is a Canadian-born American film producer and actor. He is the youngest son of telecommunications billionaire Sir Terry Matthews and Ann, Lady Matthews.
Document 2: Matthew Scurfield: Matthew Scurfield (born 2 February 1948, in Cambridge, Cambridgeshire) is an English actor and the eldest child of author George Scurfield and his wife Cecilia (née Hopkinson).
Document 3: Shippingsport Bridge: Shippingsport Bridge has been the name of three similarly-located bridges over the Illinois River in LaSalle Township, LaSalle County, Illinois: an 1872 swing span bridge, a 1929 vertical-lift bridge nearby, and a 2003 bridge in the same location as the 1929 bridge. The third bridge still exists and carries Illinois Route 351 (IL 351).
Document 4: Giles Matthey: Giles Matthey was born in Australia to a British father and an Australian mother. He moved to London with his family at the age of 2. He has one sibling, a younger sister Arabella, who is a Security Consultant. He became interested in acting during his teenage years and eventually moved to New York City. In the US, he completed a two-year conservatory program at the Lee Strasberg Theatre and Film Institute.
Document 5: Ottawa, Illinois: Ottawa is a city located at the confluence of the navigable Illinois River and Fox River in LaSalle County, Illinois, United States. The Illinois River is a conduit for river barges and connects Lake Michigan at Chicago, to the Mississippi River, and North America's 25,000 mile river system. The population estimate was 18,562 as of 2013. It is the county seat of LaSalle County and it is part of the Ottawa-Peru, IL Micropolitan Statistical Area.
Document 6: Ottawa, Kansas: Ottawa is a city in, and the county seat of, Franklin County, Kansas, United States. It is located on both banks of the Marais des Cygnes River near the center of Franklin County. As of the 2010 census, the city population was 12,649.
Document 7: Geography of Illinois: Illinois is in the midwestern United States. Surrounding states are Wisconsin to the north, Iowa and Missouri to the west, Kentucky to the south, and Indiana to the east. Illinois also borders Michigan, but only via a northeastern water boundary in Lake Michigan. Nearly the entire western boundary is the Mississippi River, except for a few areas where the river has changed course. Illinois' southeastern and southern boundary is along the Wabash River and the Ohio River. Whereas, its northern boundary and much of its eastern boundary are straight survey (longitudinal and latitudinal) lines. Illinois has a maximum north - south distance of 390 miles (630 km) and 210 miles (340 km) east - west. Its total area is 57,918 square miles (150,010 km).
Document 8: Matthew Lawrence: Matthew William Lawrence (born February 11, 1980) is an American actor and singer known for his roles as Chris Hillard in Mrs. Doubtfire, Jack Hunter in Boy Meets World, and Matt Roman in Brotherly Love.
Document 9: Tom Hadfield: Tom Hadfield (born 1982 in Wakefield, England) created Soccernet, a sports Internet company, with his father, Greg Hadfield, when he was 12 years old. Soccernet was later sold to ESPN for $40 million when he was 17 years old. Two years later, he and his father were able to raise millions of dollars to launch the education website Schoolsnet.com. Tom Hadfield founded his latest site in 2009, AeroDesigns, Inc after graduating from Harvard University, and now acts as its Chief Executive Officer.
Document 10: Andrew Sugerman: Andrew Sugerman is an American film producer. He attended the University of Rochester and subsequently the NYU – Tisch School of the Arts. Andrew began his career in television commercials and educational films in New York, then moved to Los Angeles, where he now resides, to work in theatrical feature films.
Document 11: Matthew Leitch: Matthew Leitch (born 19 March 1975) is an English actor perhaps best known for his portrayal of Floyd Talbert in the award winning HBO mini-series, Band of Brothers. After Band of Brothers, he starred in the action flick ``The Detonator ''. He is currently busy in filming Country of Hotels.
Document 12: Oklahoma: Two inland ports on rivers serve Oklahoma: the Port of Muskogee and the Tulsa Port of Catoosa. The only port handling international cargo in the state, the Tulsa Port of Catoosa is the most inland ocean-going port in the nation and ships over two million tons of cargo each year. Both ports are located on the McClellan-Kerr Arkansas River Navigation System, which connects barge traffic from Tulsa and Muskogee to the Mississippi River via the Verdigris and Arkansas rivers, contributing to one of the busiest waterways in the world.
Document 13: Rock River (Mississippi River tributary): The river begins with three separate branches which flow into the Horicon Marsh. The northermost branch, the West Branch, begins just to the west of the village of Brandon in Fond du Lac County, Wisconsin and flows east and then south to Horicon Marsh. The South Branch rises north of Fox Lake in Dodge County and flows east through Waupun to the marsh. The East Branch rises southeast of Allenton in Washington County just west of the Niagara Escarpment, and flows north and west through Theresa to the marsh. Leaving the marsh, it meanders southward to the Illinois border ending about 300 miles later at the Mississippi River at the Quad Cities in Illinois and Iowa. During its course it passes through Watertown, collects the Crawfish River in Jefferson, and receives the Bark River at Fort Atkinson. In northern Rock County it receives the Yahara River, and flows southward through Janesville and Beloit into northern Illinois, where it receives the Pecatonica River 5 miles (8 km) south of the state line.
Document 14: Peter Ivany: Peter Ivany was born in Melbourne, Australia in 1954. As Chief Executive of Hoyts Cinemas (1988–1999), Ivany grew the company to a global business with over 2,000 theatres operating in 12 countries. In 1999, he sold the business to Kerry Packer's Consolidated Press group.
Document 15: Ottawa: Ottawa (/ ˈɒtəwə / (listen), / - wɑː /; French pronunciation: ​ (ɔtawa)) is the capital city of Canada. It stands on the south bank of the Ottawa River in the eastern portion of southern Ontario. Ottawa borders Gatineau, Quebec; the two form the core of the Ottawa -- Gatineau census metropolitan area (CMA) and the National Capital Region (NCR). As of 2016, Ottawa had a city population of 934,243 and a metropolitan population of 1,323,783 making it the fourth - largest city and the fifth - largest CMA in Canada.
ground_truth: LaSalle County
sub_queries: Which city was the birthplace of Trevor Matthews? Answer: Ottawa
Ottawa >> located in the administrative territorial entity Answer: LaSalle County