1921 is the last year in which the Mint struck Morgan Silver Dollars. The coins were struck from the large and famous Nevada Silver discovery, the Comstock Lode. The 1921-D Morgan Dollar is also the only Morgan Silver Dollar that was struck at the Denver Mint. Despite being the last year of the Morgan Dollar it is also the only year in which you can obtain an example from each three different Mints. Which are the 1921 Philadephia, Denver and San Francisco Morgan Dollars.