We had a geodetic survey marker behind our house mounted in a rock outcropping near a drainage wash, and the city came by to do some work and they seem to have wiped it out. Is this something they can just do? I thought those things were sacrosanct! The work did not require them to mess with it in any way, they just seem to have made it done for no reason.
I don’t know the situation in the US, but here in the UK a lot of old benchmarks and survey markers have just been abandoned. Some of them have been preserved and accurately located using GPS and incorporated into a new network of GPS benchmarks.
Report it. Save the actual marker if you can find it. The USGS will note it so surveys will not look for it and if it is really needed, they will reset it. Knowing who knocked it out helps, sometimes the riot act can be useful. 
Somebody might be lighter by a whole $250!
I don’t know about the laws of Man bur according to God it’s a big no no.