Here is a list of Kentucky cities of approximately 20-30K in population that are close to the Ohio border:
1. Richmond 30,008
Approximately 90-100 miles from Ohio border. Richmond is the 6th largest city in Kentucky and the county seat of Madison County. It was named after Richmond, Virginia. In 2004, the city population was 30,008. By 2010 it is expected to have a population of 34,292. It is home to Eastern Kentucky University.
2. Frankfort 27,281
Approximately 65 miles from Ohio border. Frankfort is the capital of Kentucky, a state of the United States of America. It is the county seat of Franklin County. Frankfort is the home of Kentucky State University, a historically black university situated near the downtown area. Two school districts serve the city, with three public high schools located within the city limits.
3. Florence 25,449
Approximately 11 miles from the Ohio border. Florence is a city in Boone County, Kentucky, United States. Florence is the closest significant town to Cincinnati/Northern Kentucky International Airport. Florence is the largest city in Boone County, and the second largest in Northern Kentucky.
4. Nicholasville 22,878
Approximately 84 miles from the Ohio border. Nicholasville is the 14th largest city in Kentucky and the county seat of Jessamine County, Kentucky. The median income for a household in the city was $37,462, and the median income for a family was $42,978. Males had a median income of $31,536 versus $22,275 for females.
5. Radcliff 21,617
http://upload.wikimedia.org/wikipedia/en/2/27/KYMap-doton-Radcliff.PNG (broken link)
Approximately 118 miles from the Ohio Border. Radcliff is a city in Hardin County, Kentucky, United States. Its economy is largely dominated by the adjacent Fort Knox Army base and the county seat of Hardin County, Elizabethtown. The median income for a household in the city was $35,763, and the median income for a family was $41,260. Despite being in a dry county (Hardin), sales by the drink in restaurants seating at least 100 diners are allowed. Radcliff, has also, in the past, held the world record for the most fast food restaurants in a one square mile area.
6. Ashland 21,586
Approximately 106 miles from the Ohio Border. Ashland is a city located in Boyd County, Kentucky, nestled along the banks of the Ohio River. Ashland is a part of the Huntington-Ashland, WV-KY-OH, Metropolitan Statistical Area (MSA). As of the 2000 census, the MSA had a population of 288,649. Ashland boasts a 47-acre wooded Central Park that hosts an annual holiday light show, Winter Wonderland of Lights. The city is host to several summer events as well including Poage's Landing Days and Summer Motion. The median income for a household in the city was $30,309, and the median income for a family was $40,131.
7. Georgetown 19,732
Approzimately 59 miles from the Ohio border. Georgetown is a city in Scott County, Kentucky, United States. It is the county seat of Scott County. The city is named in honor of President George Washington. It is the home of Georgetown College, a private liberal arts college. The city's recent growth began in the mid-1980s, when Toyota built its first wholly-owned United States plant north of the city.