When evaluating lakes over my career, I've found most fish attracted to structure or cover absolutely love rock piles. I'd actually pick that as my Numero Uno choice. They need to be larger than most of us think...like at least 6'x 6' wide and 4-5' tall. Bigger rocks are better than small ones--rocks from softball to basketball-sized. If you'll drop a marker, like a duck decoy on a string, you can find that place again. Another hint, put a piece of 3/4" plywood across the bow of your boat, stack the rocks on that and you can drop them off by hovering over your spot, then raising the plywood. Don't load so many rocks as to make it too heavy, or to sink your boat when you raise the wood. Ask me how I know...