Linda,
Go back to the left screen. Check the label of the screen you are in. It shoudl say foothill.
If you see a long path that goes from bottom to top of screen; this means you passed it. Go back to the nest screen on top of that path and be there.
Now in this screen, stay on the leftmost side of the screen and look for a place to climb up.
See velow:

Midway up there, you cut across to the right and then up like the picture below:
