Thanks,

Since originally posting, I have been reading about concrete
construction techniques. I honestly didn't know that concrete is often
poured into the holes- I never had the opportunity to look. I am going
to do exactly what you suggested and will probably spend my memorial
day swatting mosquitoes with a trowel and the following night trying to
get concrete/mortar out of my thinning hair.
Call me stupid, but I am now at least better informed and stupid.