Kevin Costner's voice in the TV series Yellowstone has been noted as extremely rough, and fans are curious about the reasons behind it. Costner's rough voice can be attributed to his portrayal of a rugged and weathered character, John Dutton, who is a Montana rancher. The actor has deliberately chosen to speak in a gravelly deep tone to add authenticity and depth to his character's persona. This choice has been appreciated by viewers who find it fitting for the rugged Western setting of the show.