trackless

adjective3

1. •
   Of a place: not having tracks or paths; pathless, untrodden; also, having had all tracks removed.

   • Associates! Solitude in trackless deserts, / Where locusts, ants, and lizards poorly thrive,— / […] / Were to an honest heart endurable, / Rather than such associates. — 1836
2. •
   Of a train, tram, etc.: not running on tracks.
3. •
   (literary) Leaving no track or trace when moving; also, not following any track or path.