You are right. I looked up the history of rope-making and there is evidence that Neanderthals made rope 40,000 years ago! The first specialized tools made to make rope were found in Egypt. "Egyptian rope dates back to 4000 to 3500 BC and was generally made of water reed fibres. Other rope in antiquity was made from the fibres of date palms, flax, grass, papyrus, leather, or animal hair."
Still, you have to hand it to them...climbing that mountain with long ropes and then rappelling 250 feet down the cliff face to hide objects in that cave. Wow.
Here's a page from the "User's Manual for Rope Making, v1.6"