Big Sky is an American crime drama thriller television series created by David E. Kelley and based on The Highway series of books by C. J. Box. Katheryn Winnick and Kylie Bunbury star as a pair of investigators who team up to work on multiple cases in Montana. Dedee Pfeiffer also stars. Brian Geraghty, Jesse James Keitel, John Carroll Lynch, Anja Savcic, and Omar Metwally join them for the first two seasons, while Jamie-Lynn Sigler and J. Anthony Pena join them for the last two seasons. Also starring in the series are Valerie Mahaffey, Natalie Alyn Lind, Jade Pettyjohn, Ryan Phillippe and Ted Levine in the first season, Janina Gavankar and Logan Marshall-Green in the second season, and Jensen Ackles and Reba McEntire in the third season.