Simplify the following text for a Grade 15 native English-speaking person.
Original: Clarksville is the principal central city of the Clarksville , TN-KY metropolitan statistical area , which consists of Montgomery County , Stewart County , Tennessee , Christian County , Kentucky and Trigg County , Kentucky .
Simplified: Clarksville is the principal central city of the Clarksville-Hopkinsville metropolitan statistical area , which consists of Montgomery County and Christian County , Kentucky .