Breakdown of 2011 ASEs: Available Separately Proof: "W" mint mark Uncirculated/Burnished: "W" mint mark Bullion: Produced at San Francisco and West Point, neither have a mint mark. Note, however, that this hasn't stopped NGC and PCGS from slabbing coins as (W) or (S) if they receive complete sealed Mint boxes that show which facility they were produced at. 25th Anniversary Set All 3 of the coins above plus: Uncirculated/Burnished: "S" mint mark Reverse Proof: "P" mint mark