I've visited a lot of caves and rock formations and almost always, I've found graffiti in these places. I found numerous examples at Hocking Hills over the weekend.
One interesting thing I've noticed is that many tour guides will point out old graffiti, usually from the 1800's, but will also ask that people refrain from adding to it. While this is totally understandable, I think it's worth noting that the only difference between the grafitti pointed out by tour guides and that discouraged by them is age.
Carving into rocks destroys them over time, but the carvings also serve as a sort of ledger or log. You can see who was where and when, and sometimes even what they were doing. Teens who carved names and dates into Rock House in 1890 probably did not get into trouble since those areas were not protected at that time; teens who do the same in 1990 could have been kicked out of the park or worse.
My question is, how much time must pass before we regard carved graffiti as historic rather than with disdain? I saw some from the 1980's and it seemed to mar the rock surface, but another inscription from 1809 fascinated me. Is the difference that the features of Hocking Hills were once just part of a larger wilderness, something that was expendable since so much of the country was still uninhabited? Is it that old human instinct to mark something not everyone could find? Now that we have fewer and fewer of these beauty spots to visit, they become more valuable and there isn't the need to claim where you have been, since so many have been there before. Perhaps that instinct to commemorate a visit still lingers, even when it no longer means anything.