As part of the effort to prevent the extermination of the largest land mammal of North America, San Francisco began a captive breeding program in 1891. Originally, the herd began with the purchase of a “family”: one cow named Madame Sarah Bernhardt and a bull named Ben Harrison, from Wyoming and Kansas, respectively. Their paddock was located just east of the present-day Academy of Sciences and some were moved to the current location in an area in the western end of Golden Gate Park in 1899. With the addition of 3 bison in 1905 from Yellowstone National Park, by 1918 the herd had grown to 30. (Not sure how many bison are in the herd today; at least a couple dozen, judging by a recent ground-level appraisal).