KY 107's southern terminus is located just south of the Christian County community of LaFayette, near an entrance to the Fort Campbell Military Reservation, falling just short of the Tennessee state line.

It then goes over I-169 (the Edward T. Breathitt Pennyrile Parkway), and then makes a turn to the north-northeast at an intersection with KY 507 (Pilot Rock Road).

Until the Fort Campbell Military Reservation was established in 1942, KY 107's southern/western terminus was at the Tennessee state line in the southeastern-most corner of Trigg County.

The southern terminus was truncated to the intersection with Angels Road when the military base was opened.

The roadway between Clifty and Lewisburg was undesignated until KY 107 was extended onto that road in the mid-1950s.