The mountain beaver (Aplodontia rufa) is a species of rodent that can be found in two different regions:
- British Columbia to Humboldt County, California.
- Mt. Shasta, CA to Western Nevada.
This rodent is the only existing species within its genus Aplodontia.
Mountain beavers are known to be asocial animals, tending to create overlapping burrows alongside rivers, creeks, streams, and other water sources near second growth forests. They will rarely leave their burrows past far distances and are very protective of their homes. Mountain beavers have poor senses of sight and hearing but heightened sense of touch and smell make up for these deficiencies.
Mountain beavers can be identified by their dark brown fur, with characteristic white spots of fur behind their ears. Their bodies are small, but stout and have short limbs as well. Unlike the long flat tails of American beavers, mountain beavers have a short tail and are actually more similar to a tailless muskrat in appearance.
Mountain beavers are herbivorous animals, and eat a wide variety of plants as a part of their diet. They enjoy eating ferns, nettles, dogwood vegetation, brambles, fireweed, and salmonberry. These rodents have inefficient kidneys and need to drink a third of their body weight every day in water to stay hydrated.