The Prairie Rattlesnake (Crotalus viridis viridis) is a subspecies of the Western Rattlesnake. Prairie Rattlesnakes are found 10-15 miles east of the Missouri River and western South Dakota, in the open prairies, haylands, and croplands -- any area with an abundance of food. They eat animals such as mice, ground squirrels, and the young of prairie dogs or cottontail rabbits. They also eat other snakes, lizards, birds, and insects. The average snake will consume 2-3 times its own weight in various food items during the spring to fall months when the snake is away from its winter den.
Because the Rattlesnake is cold-blooded, it cannot survive the harsh winters above ground. In the early fall, the snakes will begin moving towards the winter dens, normally found on hillsides, bluffs, and rocky outcrops with underground openings. Snakes will also den up in holes or burrow systems of prairie dogs or other animals. Some of these sites have been found to hold as many as 1000 snakes during the winter. When summer comes again, the dens are abandoned and the snakes will travel 2-4 miles from their den. Snakes return to the same den year after year, provided the den is not disturbed or destroyed. These dens or hibernaculums have been used by many generations of snakes over the years.
Most snakes are oviparous and lay a leathery egg to produce young. The Prairie Rattlesnake is ovoviviparous and give birth to live young. A female gives birth to 8-12 young every other year.
The Prairie Rattlesnake, like all rattlesnakes is venomous. This is the only venomous snake in it's territory. Very few people actually come in contact with Prairie rattlesnakes, however, as the creature is shy and will avoid contact whenever possible. The fangs are less than 1/2 inch long, but the poison is strong. The poison of the young is up to 12 times as strong as the adult poison. | 
