How to Make Papier-Mache Mountains?

How big do you want your mountains to be? If you want them to be fairly small e.g. for a small Christmas garden display, you could make a cardboard cone and start laying on glued strips of paper. Keep adding and smushing the glued strips until you have achieved a mountain shape. OTOH if you want a really big mountain, that would require an infrastructure of wire mesh. But the procedure would be the same. Just keep layering glued paper until your structure starts looking like a mountain. Good luck with your project!

For your paper mache you could use old egg cartons. Put water and egg cartons in blender and blend and drain and squeeze water out and shape it over whatever you are using as your mold.