Silverpath is the terms cats use for train tracks that Thundersnakes run along.
The Silverpath leads to many different places in and out of the city. They are usually located near Twolegplaces. Every once in a while, the Silverpath runs alongside a big Twoleg den, known to Twolegs as a train station.
The Silverpath usually appears in the tunnels, or in open fields where Thundersnakes ride along. The tunnels lead into the ground, are dark, and very noisy.
After meeting two kittypets who direct Tigerheart in the right way to reach the city, he plans to walk along the Silverpath to the large Twolegplace. He begins his journey, when the Silverpath disappears into a gaping hillside, and hears a Thundersnake roaring down the tracks toward him. It howls past, then vanishes.
Much later on, as Tigerheart makes the journey back to the Clans, Lightkit is nearly hit by a Thundersnake as she plays on the Silverpath. Spire directs them away from the tracks, backing up his actions by claiming there will be death if they stay.