The Cairn, while serving a wide variety of purposes throughout the world, and possibly here in Nevada also, for what I’m doing, is usually serving one very useful purpose. For me it’s marking the trail.
Some places, like say the wood hillside of mountain, not such a big deal, pretty, but not so necessary. Out in the open desert though they can be very useful to let you know you’re going the right direction. Or when walking up a wash cairns will be placed to let you know you should still be in the wash, though it’s good to look around when you come to one because they can also mark where the trail exits the wash.
Personally, big fan of the simple solution to a simple problem. Also gotta give props for the feats of balance people occasionally pull off with them.