When one goes hiking one usually relies on trail markers of one kind or another. Back east, these are commonly in the form of colored paint swatches on the trees by the trail.
Out west they are usually in the form of stacked stones alongside the trail…which I find quite interesting because nobody ever seems to disturb them other than to add more stones.
Apparently, vandals and hoodlums don't go hiking out west because moving or knocking down cairns seems like just the thing a vandal or hoodlum would do to release all their built up tensions ad disdain for order. Perhaps they don't like being alone? Or maybe they are afraid of getting lost if they knock them down…