Montgomery County is a county in the U.S. state of Tennessee. As of the 2020 United States census, the population was 220,069. The county seat is Clarksville. The county was created in 1796. Montgomery County is included in the Clarksville, TN–KY Metropolitan Statistical Area.

Robertson County is a county located on the central northern border of Tennessee in the United States. As of the 2020 United States Census, the population was 72,803 people. Its county seat is Springfield. The county was named for James Robertson, an explorer, founder of Nashville, and a state senator, who was often called the "Father of Middle Tennessee." Robertson County is a component of the Nashville-Davidson–Murfreesboro–Franklin, TN Metropolitan Statistical Area.