Authorities say the man was with his son outside their cabin when they saw the poisonous snake.
The boy says his father picked it up and that's when it bit him.
The local sheriff's office was called.
They arrived and found the man unresponsive.
Experts say his body's reaction to the snake's venom likely caused his death.
"Most of the time when people die from a copperhead bite, which is usually what they say, it's usually not from the actual bite, it's because they had a previous medical condition," said Sara Turner with the Missouri Department of Conservation.
About 200 people in Missouri are bitten by copperheads each year.