Distribution and Abundance. In the United States, boreal toads occurred historically from southeastern Alaska south to northern California, and east to Montana, Wyoming, Colorado, and New Mexico (Stebbins 1985). In Canada, they occur in Alberta, British Columbia, and the Northwest Territory. West of the Rocky Mountains to sea level, the boreal toad is found in dry habitats (Xxxxxxxx 1985). In Colorado and Wyoming this toad is found near surface waters along foothills, mountain xxxxxxx, and xxxxx sub-alpine forests. With the possible exception of New Mexico, boreal toads continue to be found throughout their historic range. However, within this broad historic range, some areas of distribution have been greatly reduced. This trend has also been well documented with numerous other species of amphibians throughout the world (Xxxxxxxx 1994). These world-wide declines of amphibians have often been perplexing because causes of decline are not always obvious. However, recent discovery of the role of the chyrtid fungus in amphibian declines point to this pathogen as the proximate cause of the deaths for at least some species, such as the boreal toad. Boreal toads found in New Mexico, Colorado, and southeastern Wyoming form the SRMP; a group of toads that is geographically separate from boreal toad populations in Utah, northwestern Wyoming, and the Pacific Northwest (USFWS 1994). Southern Rocky Mountain boreal toads were once considered common to abundant throughout the higher elevations of Colorado and southeastern Wyoming along the Snowy and Sierra Madre ranges (Medicine Bow, Sierra Madre, and Pole mountains) (USFWS 1994; CDOW 1994). The southern periphery of the species range was located in New Mexico along the San Xxxx Mountains at Lagunitas, Canjilon, and Trout Lakes (USFWS 1994; Xxxxxx and Painter 1994). Specifically, the geographic areas, or mountain ranges, of historic occurrence of the boreal toad in the southern Rocky Mountains are: This area extends from south-central Carbon County, WY, through western Xxxxxxx County and eastern Routt County, CO, along the continental divide to approximately Rabbit Ears Pass. It is located primarily on the Routt and Medicine Bow National Forests. This mountain area is in western Routt County and eastern Moffat County, CO, northeast of Craig. It is located primarily on the Routt National Forest.
Distribution and Abundance. Sub-criterion Bi: Small and Resident Populations Areas supporting at least one resident population, containing an important proportion of that species or population, which are occupied consistently. Sub-criterion Bii: Aggregations Areas with underlying qualities that support important concentrations of a species or population.
