Sierra 117 Instructions:
Ok, I went through the mission again and it is after you go through the forest where there are nothing but jackals up in the trees. (After you see the pelicans get shot down). If you stay on the left side you will get to a point where there is a tiny ledge that leads to another bigger ledge. In the corner you will see the monkeys with the guys face. Hope that helps. If nothing else, use a saved film like I did.