For bankers in fledgling Denver gold dust was proving an unwieldy and expensive form of exchange. Accordingly, Clark, Gruber, and Company set up a private mint and began minting pure gold coins on July 20, 1860 bearing the name of the company. Fully legal, the mint produced $3,000,000 in coins over the next thirty months. The U.S. Treasury authorized the Denver Mint in 1862 and purchased the operation in 1863. (By John Osborne)