Fifty-three species of mammals known from Harding County, South Dakota,
are treated in the accounts that follow. Appended is a brief discussion
of 10 additional species that may be found there. In most accounts,
specimens that have been examined (a total of 644) are listed in
telegraphic style preceding remarks; localities are arranged from north
to south in such lists. Unless otherwise noted, specimens are housed in
the Museum of Natural History. All measurements are in millimeters
(those of embryos are crown-rump lengths) and weights are given in
grams.