13 years later
Thirteen years ago, I made a control survey around about 24 blocks along one edge of the campus of The University here in Austin.
That's a 3/8 in. steel spike set in a drill hole with a 2 in. aluminum washer for identification.
I had occasion to go back this afternoon to see what was still in place, ready to use for some further surveying. Amazingly enough ... everything I looked for was still there.
The punchmarks on the 3/8 in. spikes were still perfect, the aluminum washers legible. I've had particularly good luck with this mark since it is easy to install, hard to deface the station mark (the spike), and not fancy enough to look as if it's worth trying to steal.
Murphy's Law practically guarantees that things can't be this easy, but the thing about Murphy's Law is you can't rely upon it. So, who knows?
Kent McMillan, RPLS Austin TX