In level 6 when you get off the train, walk to the right. Click on left-most sheep to herd them to the right. Move to where they were. If done correctly, the screen will pan right.
Repeat by clicking on the left-most sheep and then moving to where they were. The screen should pan right again.
Click on the left-most sheep again and then move to where they were. The screen will not pan this time. Move to just below where the hill with the rock wall meets the top of the right-most hill.
Click on the right-most sheep and the sheep will head back towards you and then jump to the hill with the rock wall. Proceed all the way to the right and the screen should pan followed shortly by your achievement.