Absolutely true. Won’t make me do it, but absolutely true.

I think I had to be so organized my whole life that I have Retirement Stubbornness, a not very rare disease when you get out of harness.

Sometimes they are trail markers. Sometimes they are there "just because".
You may want to look at this about cairns.
https://en.wikipedia.org/wiki/Cairn

Cairns have been and are used for a broad variety of purposes. In prehistory, they were raised as markers, as memorials and as burial monuments (some of which contained chambers). In the modern era, cairns are often raised as landmarks, especially to mark the summits of mountains. Cairns are also used as trail markers. They vary in size from small stone markers to entire artificial hills, and in complexity from loose conical rock piles to elaborate megalithic structures. Cairns may be painted or otherwise decorated, whether for increased visibility or for religious reasons.

man-made pile of stones or burial monument

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