Mountain Beavers. Photo Credits: Top Left: Gary Fellers, USGS; Top Right: Gary Fellers, USGS; Bottom: Chris Wemmer, California Academy of Sciences.

The muskrat-sized mountain beaver (Aplodontia rufa) is a primitive species of rodent that lives in underground burrows, coming out at night to feed on a wide variety of vegetation. Their range extends from southwest British Columbia through western Washington and Oregon. In California, they live in the Sierra Nevada Mountains, and along the coast south to near Cape Mendocino and in isolated populations at Point Arena and Point Reyes. The Point Reyes mountain beaver (Aplodontia rufa phaea) is an endemic subspecies that is only found in western Marin County almost entirely within Point Reyes National Seashore. The Vision Fire of 1995 burned over 12,000 acres including 40% of the known range of the Point Reyes mountain beaver. Biologists believe it may be as long as 20 years before the population fully recovers.