Up on the plain the driver appears to move arbitrarily between barely visible tracks.

Then he saw the barely visible track leading down the mountain- side, and relaxed a little.

Just beyond it was a barely visible track of a boot heel in the soft earth.

Quite a few animals that he tracked had simply ceased to make visible tracks; they vanished.

He followed the tracks, dimly visible in the light layer of snow.

The snow here was untrampled; the only visible tracks were those of a wolf spider.

Piemur found another rock and, rising, went to the now visible track.

Only where the cutter went through a large drift were there visible tracks.

He was over solid ground now, with the roughly defined track of the Way visible below him.

Directly before him on the scarcely visible track lay the entrance to the hidden cavern, the door still open.