The black toad, Bufo exsul, has one of the most restricted ranges of all anuran amphibians. Its habitat is located almost entirely on land owned by Deep Springs College within Deep Springs Valley, Inyo County, California. Although abundant within its habitat, it is listed as threatened by the California Department of Fish and Game, primarily because of the small size of its range. Many aspects of its natural history remain unknown, making scientifically based conservation difficult. Potential threats to the black toad population might include the unquantified effects of cattle grazing, well-intentioned but non-scientifically based conservation efforts, changes in water availability, and other factors that have been implicated in the decline of amphibians worldwide. A census performed in part of the range of the toad in 1978 estimated a population size of 7,897 to 9,744 toads. We censused this population in 1999 and estimated 8,419 toads, with a 95% confidence interval of 5,624 to 16,740. The current population size is consistent with previous studies; however, continued monitoring is required to detect future changes. We summarize observations on changes in the sex ratios, average body size, and habitat conditions, and we recommend future research that might effectively guide conservation efforts.