Just above the wall is a section of the railroad that is no longer in use but is accessible to intrepid hikers. The tracks have been removed, and the path is now an unmarked trail. More than 7,000ft in elevation, it opens up to picturesque views of Donner Lake in the distance. It"s here that hikers can walk through a series of tunnels, including the nearly 1,700ft-long Tunnel No 6 – the longest of the 15 tunnels bored through the mountains – along with snow sheds that were built to protect the tracks.