We went to our local tire repair shop and asked if we could raid their piles of old tires. The tire shop was quite happy that someone wanted to take a few tires off their hands and said yes. There were a number of large tractor tires, smaller tractor tires, tires from back hoes, semis, and so on. We collected 5 large tractor tires, 4 smaller tractor tires, 4 back hoe tires, and two dozen large truck tires. It took two loads of piling as many on the trailer as we could. Each tire was filled with soil and manure then carefully leveled off.