Wolf Pack (Used Book) - C.J. Box
Wyoming game warden Joe Pickett encounters bad behavior on his own turf--only to have the FBI and the DOJ ask him to stand down.
The good news is that Joe Pickett has his job back, after his last adventure in The Disappeared. The bad news is that he's come to learn that a drone is killing wildlife--and the drone belongs to a mysterious and wealthy man whose grandson is dating Joe's own daughter, Lucy.
When Joe tries to lay down the rules for the drone operator, he is asked by the FBI and the DOJ to stand down, which only makes him more suspicious. Joe discovers that the man is in the witness relocation program, as he is in possession of knowledge about dangerous people. Soon, Joe comes across a pack of four killers working on behalf of the Sinaloa cartel to find the man in the WITSEC program--and Joe realizes his actions might expose the man.
Teaming up with a female game warden (based on a real person, one of the few female game wardens at work in Wyoming today) to confront these assassins, Joe finds himself their prey--along with Lucy and her boyfriend.
Joe Pickett, #19