>Here in the northern part of West Tennessee, there aren't that many "natural" rocks lying around.
Heh. I know that rocks are scarce in some parts of the country.. hard for me to relate to since here in the northeast, they're everywhere. For several hundred years farmers have been hauling them out of fields, building walls, making piles, filling holes, and building with them. They're everywhere. When the glaciers receded 10,000 years ago, their load of rocks, gravel, and sand were just dropped. Much of our subsoil, where we actually have subsoil, is "glacial till", a pudding of clay, sand, gravel, and rocks of all sizes. It's hard diggin...
A beekeeper here once said that the most valuable and least expensive piece of beekeeping equipment is the rock on top of your hive. Rock, concrete block, bricks, chunks of wood, whatever it takes to keep the lid on.
Good deal with the blocks. Here they cost $1.25 each, and most of mine end up in the lake with a rope through them for boat moorings, for which they're quite suitable, if you use a piece of chain through them lest the rope chaff and your boat goes on the rocks... a lesson I learned the hardway, several times.