The dens are the winter home of roughly 70,000 red sided garter snakes. Their winter dens are caverns formed by the area’s water-worn limestone and bedrock. In the spring, they come up from their dens to the snake pits and then they scatter into the nearby marshes for the summer.  The pits contain the largest amount of this type of snake in the whole world! Birds are the most serious predators and many red-sided garter snakes are killed by crows, magpies, owls and hawks. The Narcisse Snake Dens are a very interesting place to visit and learn about.