Into Mt. Pony the Federal Reserve built a 400 foot long, radiation hardened, underground bunker of steel–reinforced, one–foot thick concrete. This high The Federal Reserve facility in Culpeper.security 140,000 square foot facility provided storage for around $3 billion worth of U.S. currency, all neatly shrink–wrapped and stacked on pallets 9 feet high. The currency was meant to be used to replenish money supplies in case of nuclear attack.