Small mammal populations are a significant but often overlooked component of ecological communities. Small mammal populations although a key component of our ecosystems, have been little studied in comparison to other ecosystem components, and this is especially true in relationships to human disturbances. Based on the literature, it is apparent that recreationists affect wildlife through direct disturbance of normal activities. Decision-makers and natural resource managers are advised that any analysis of proposed changes in human activity should, as a first step, determine the sensitive species, keystone species, and sensitive habitats that may occur in the area under consideration. Information from the Montana Natural Heritage Program is used to highlight sensitive species and keystone species for Montana, and associate them with their particular habitats. Additionally, several of the more sensitive Montana habitats or environments are discussed in more detail, e.g. alpine habitats, bogs, subnivian environments, and bat habitats. Some specific and documented recreational impacts on small mammals are also discussed along with long-term and cumulative impacts. Guidelines and recommendations, based on the authors interpretation and synthesis of the available literature, are provided as well as the most urgent research and informational needs concerning recreational impacts to small mammals.