For some reason a lot of the males of our species have a compulsion to write on the walls of public restrooms they visit.
To accommodate this compulsion Under-The-Hill Saloon provides a blackboard for these aspiring authors. However, it appears some authors did not want their comments to be easily removed, so their notes migrated to the nearby walls.
Also, new authors appear to have no respect for previous authors, or, they must cherish certain locations on the walls because they tend to write their comments on top of previous comments or names.
Most graffiti at Under-The-Hill Saloon looks like a "guest book" with the author's name, date of their visit and their hometown displayed. But occasionally an artist, or poet, drifts through and leaves us a drawing or a poem to enjoy.
We must point out that ladies have no such compulsion, at least not to the extent of the males of our species.