I am looking for trees marked in white with the number 90.

Typically used to mark dead trees, it works beautifully on sand.

This expedition found only a couple of trees marked "L".

In addition, they are used for marking trees to establish territory and occasionally as weapons.

She stopped beside a tree marked with a blaze and waited for the others to catch up.

Most of the trees marked for removal are on the rejected speedway site.

They are the birds of good omen, who would never roost in a tree marked for felling.

Hovell recorded seeing trees already marked by steel tommyhawks.

She carved another blaze on a tree, then began cautiously probing into the woods, marking trees as she went.

They marked trees around the Devil's Den with their danger sign(a sideways V), and never returned.