Thank you for getting our general geologic context in order, Laurie.
And I agree, the source of this material is worth investigating.
To answer your question, dirtslanger, I did a quick Google search of gravel suppliers in your area.
You can scratch the big MartinMarietta and Vulcan quarries out because they are blasting and crushing rock
for gravel, which wouldn't be the source of this gravel.
Of course I haven't seen the gravel and am assuming that it was transported by truck to where you are finding it.
But, I think the "original" source has got to be an alluvial deposit along a river basin
where all these agate pieces were transported and deposited together with the other gravels.
This could be a Mom & Pop operation and Sam just hauls and sells for them. Infact, around here we find this type of material
in the old sand quarries where the rocks are separated out.
On his Homepage description of gravel he talks about it being "River Gravel" and "Pea Gravel".
I don't know if Sam is the one digging it, but he might know where it could be coming from.
Probably just a bunch of legwork.
I did notice a big hole that looks like it needs to be looked at behind the Mill Creek Country Day School
on Hunter Rd, Ooltewah, if it's still there.
Rock On!