Western North America in southeastern British Columbia, Canada, southeastern Washington and northeastern Oregon; extend as far east as western Montana and south-central Idaho.
Almost exclusively inhabits rocky, cold, forest streams with quickly moving water. If found away from a water source, it is usually only during an especially wet night. When weather is dry, will move to wet areas by water sources like stream banks. Diets differ between larvae and adults with larvae eating diatoms and adults ingesting a diverse mix of invertebrates and insects.
Dorsum, or base color, is either brown or gray and exhibits a bumpy texture; has either brown, gray, or yellow spots throughout body. Rear feet commonly have one outer toe that is noticeably larger than all other toes. Total adult length can range from 1.5 to 2 inches. Only the male has a protrusion that resembles a tail. This acts as a penis during mating which usually takes place from September to November. Even though eggs are laid in early summer at a nest site, larvae can stay at the site for a year. One of the few frogs that breed through internal fertilization.
Learn more with Schechter Natural History's Guide to Reptiles and Amphibians