trail

bridle path

towpath

alley, alleyway, bypath, byroad, bystreet, byway, passageway, walkway

cutoff, shortcut

lane, pass, passage, road, roadway, route, row, run, runway, street, thoroughfare

footprint, footstep, hoofprint, path, rut, step, tread

artifact, leavings, relic, remain(s), remainder, remnant, residual, residue, sign, spoor, token, vestige

clue, cue, hint, indication, inkling, intimation, lead, suggestion

scent, shadow, whiff