The experimental brass-clad copper dollar was struck for circulation only in 2000 and 2001, but a limited number of these golden-color dollars have been struck for collectors each year since. The coveted finest-quality proof is the most elusive form of the Sacagawea dollar. This 2001 issue's 3.1 million output was one of the lowest mintages of finest-quality proofs struck by the San Francisco Mint. And it's the key scarcity of the series. Finest-quality proof minting with deep-etched frosted engravings and dazzling mirror backgrounds. The 2009 releases featured a new look.