Rare KEY 2012 United States Mint Proof Set - 14 Coins Included Very Low Mintage. 2012-s United States Mint Proof Set with 14 coins. Produced at the San Francisco Mint, this proof sets contain a Lincoln Cent, Jefferson Nickel, Roosevelt Dime, Kennedy Half Dollar, Sacagawea Dollar, 4 Presidential Dollars and 5 America the Beautiful Quarters. The quarters are El Yunque National Forest, Chaco Culture National Historical Park, Acadia National Park, Hawaii Volcanoes National Park and Denali National Park. The Presidents are Chester Arthur, Grover Cleveland (1st Term), Grover Cleveland (2nd Term), and Benjamin Harrison.