@RustyCrab the mystery lake prepper cache is a bit easier to find than I thought
up the rope, go right and there will be a cave downhill to the left. stay above it, go right around the giant rock, there should be rabbits running around in front of you, go right more and up the steep hill and the prepper cache is in a little depression up there
the one I got this time was the kitchen version, lots of food, distress pistol, and some good clothing