In the last post I discussed how many 2009 District of Columbia coins were produced for circulating in Philadelphia and Denver. I did not mention those that were minted in San Francisco.
Coins minted in San Francisco will have a “S” mark instead of a “D” or “P” under the words “In God We Trust.” However, it will be a PROOF coin and not a coin created for circulation but instead for collectors.
There were 2,108,943 District of Columbia (2009) proof coins minted in San Francisco. There were 993,589 Proof coins that have SILVER minted in San Francisco.
Below is a description from Wikipedia about the mint facility in San Francisco.
The San Francisco branch, opened in 1854 to serve the goldfields of the California Gold Rush, uses an S mint mark. It quickly outgrew its first building and moved into a new facility in 1874. This building, one of the few that survived the great earthquake of 1906, served until 1937, when the present facility was opened. It was closed in 1955, then reopened a decade later during the coin shortage of the mid-60s. In 1968, it took over most proof-coinage production from Philadelphia, and since 1975, it has been used solely for proof coinage, with the exception of the Anthony dollar and a portion of the mintage of cents in the early 1980s. (These cents are indistinguishable from those minted at Philadelphia.)