John,
Knockem Hill BBQ is in Hearndon,KY a few miles off exit 86 of I-24 between Hopkinsville and Ft Campbell. It’s kinda out-of-the-way! Pov.Pete says to be sure to check ahead for operating hours of the place as it is ‘small’ and the possibility of running out of the ‘Chops’ is real , if they get a lunch rush! There’s a thread with more info about the place on the BBQ Forum.