Where are Wander and his siblings born in the novel, A Wolf Called Wander?

The tunnel is where Wander and his siblings were born. They remain entirely inside for a period of time, but Wander is ready to explore when his mother finally gives him permission. The tunnel is a small cave, made by Mother. It is designed to keep the pups safe from other animals and from the weather. An important part of the tunnel is how is smells. Wander returns to the tunnel for awhile, even after he is allowed to begin exploring the area.