Instructions
Play "Pitfall: The Lost Expedition" until you get to Chapter 10. This is where the pickaxe is.
Open the glowing door at the start of chapter 10 and you will see the pickaxe. Walk over to it to pick it up. Pitfall Harry can now use it to climb up steep mountainous areas.
Use the pickaxe in the beginning of Chapter 11 to climb up the purple crystal walls.