Trackless

The explorer pushed his way through the trackless mountain region.

a trackless desert    a trackless forest

Associates! Solitude in trackless deserts, / Where locusts, ants, and lizards poorly thrive,— / […] / Were to an honest heart endurable, / Rather than such associates.

In a country so vast as Canada, nothing but the railway could possibly save it from remaining a trackless, undeveloped wilderness.

"You got two feet, Sethe, not four," he said, and right then a forest sprang up between them; trackless and quiet.

At about this point, Seivarden and her two Amaats had made it into a cramped and dim access corridor behind the governor's residence. It had probably at one point been meant for servants to use to go unobtrusively back and forth, but hadn't been used in years; the floor was dusty and trackless.

The two structures remain in a remarkable state of preservation, despite finding themselves adrift and trackless in the County Down countryside, after the closure of the station and the line in the 1950s.

What was it that I loved so well about my childhood's home? / It was the wide and wave-lashed shore, the black rocks crowned with foam! / It was the sea-gull's flapping wing, all trackless in its flight, / Its screaming note, that welcomed on the fierce and stormy night!

a trackless trolley