timber line
timberline
tree line

He came through the last line of trees into the green light.

Ahead was a line of trees, which might mean small game.

We've got a lot of movement beyond the tree line.

When we got above the tree line, though, things started to go wrong quickly.

He went to the tree line to do his morning business, then came back to the food.

Only a few miles to the west was the tree line.

At the far end, just in front of the tree line.

"Can you not see how near the first line of trees is now?"

A few had made it to the line of trees.

Minutes passed, and still no movement in the tree line.