I've got one of them that went in on a rocky caliche bed in about '87. Don't exactly remember the year. That whole area is now a muddy mess. 23? years of cattle poop, residual water out of the trough, and grass taking off seems to have created somewhere around 4 inches of top soil that turns into murky messes such as the one I am seeing now. There is layer upon layer of limestone underneath, but you'd never know it in a picture.