SD Bison Gold Coins. The SD Bison coins (aka SD Buffalo coins) were made in the Black Hills of South Dakota. They were made in three years, 1987, 1988, and 1989. In 1989, the records were not kept very well. It is estimated the quantities were 1/2 of the 1988 sales. The 1989 quantities below are based on rumor and word of mouth.