The Collaborative International Dictionary of English v.0.48:

Trackless \Track"less\, a.
   Having no track; marked by no footsteps; untrodden; as, a
   trackless desert.
   [1913 Webster]

         To climb the trackless mountain all unseen. --Byron.
   [1913 Webster] -- Track"less*ly, adv.-Track"less*ness, n.
   [1913 Webster]