In the two pics below are iron pipe monuments I found on a recent boundary survey we performed in Brentwood, California. One pipe was under a fence. The other was cast into the concrete footing of an outbuilding. Neither monument could have been found with a pin-finder. We found them using a rag tape, information from the historic survey maps, and our sniffers.
This is an example of why I put my boots on every single property that we survey here at Redefined Horizons. That is a level of attention you just don’t get at most engineering/surveying companies. I’ve worked at places where there was 3 or four levels between me and the field crews.
If your land development project or real estate transaction in Central California isn’t getting this level of attention, you need a new boundary surveyor. Reach out to me at firstname.lastname@example.org or 209-298-7521.