Home-range size and population abundance indices of coyotes (Canis latrans) have not been documented in Wind Cave National Park, South Dakota, USA. In 2003 and 2004, we captured a total of 26 coyotes and radiocollared 22 adults (12 F, 10 M). In 2003 and 2004, 2 of 17 (12%) and 5 of 9 (56%) coyotes, respectively, were infected with sarcoptic mange (Sarcoptes scabiei) at the time of capture. Thus, objectives were modified to document effects of the mange epizootic on the coyote population. In 2003, home-range (adaptive-kernel) sizes for male coyotes with mange and those considered healthy were 8.26 ± 1.63 (SE) km² and 9.67 ± 2.80 km², respectively. In 2004, home-range sizes for those male coyotes with and without mange were 22.69 ± 9.06 km² and 12.51 ± 2.73 km², respectively. Male home-range size did not differ between years (P = 0.14) or by status (with or without mange; P = 0.84). Survival of collared coyotes was 60% at the end of 2003. Results from fecal line transects, an index of relative abundance, indicated that the coyote population decreased by 48% from 2003 to 2004. Continued monitoring of sarcoptic mange epizootics will enable managers to assess the effects of mange on coyote populations.