Elgin is a city in northern Illinois, located about 40 miles northwest of Chicago. It has a population of over 110, 000 and is the eighth-largest city in the state. CAIRO is a city in Alexander County, Illinois, located at the confluence of the Ohio and Mississippi rivers. It has a population of around 2, 800 and is the county seat. Olney is a city in Richland County, Illinois, located about 70 miles east of St. Louis. It has a population of around 8, 500 and is the county seat.