Firewood purchasing permits are available at Lake Red Rock. Tracy Spry with the US Army Corps of Engineers says permits are required to buy firewood from the Corps. She says the wood comes from trees that have been cleared for maintenance and construction purposes, or if a particular variety of tree is overpopulating an area of the park. A variety of hardwoods are available at the South Tailwater service entrance at a cost of $5 for a small pickup load and $10 for larger loads.