Many parks and nature preserves have restricted access and "do not walk off the trail" signs.

No man was Tonto's equal at following a track, or reading trail signs.

His eyes had grown old in the reading of trail sign and the motives of men-and women.

Unschooled in civilized ways Conan might be, but he could read trail sign.

His gravestone bears a circle with a dot in the center, which is the trail sign for "I have gone home":

As of 4-1-2010 the trail sign was no longer there.

Moreover, he could read trail sign like most men could read a newspaper.

We'll scatter out to cross that ridge and look for trail sign.

After that, I was able to follow his trail signs easily.

Right there, one of them got down and snooped along the ground, obviously looking for trail signs.