Indiana State Police says it happened around 10 Wednesday night on State Road 56, near Haysville.
Troopers say 50-year-old Donald Humphrey was heading west on 56 when he lost control of the truck.
It rolled over and slid off the road.
Humphrey was pronounced dead at the scene.
Many of the turkeys, we're told, also died.
State Road 56 was closed for more than five hours but is now back open.