On October 1, 2010, the California Fish and Game Commission declared the mountain yellow-legged frog a candidate species (PDF) as defined by section 2068 of the Fish and Game Code.  The Commission accepted the petition to list the mountain yellow-legged frog as endangered at its September 15, 2010 meeting.  The Center for Biological Diversity previously submitted (PDF) a petition to the Commission to list the mountain yellow-legged frog as endangered on January 27, 2010.  The Commission transmitted the petition to the California Department of Fish and Game for review.

The mountain yellow-legged frog consists of two species.  The southern mountain yellow-legged frog (Rana muscosa) is native to the southern Sierra Nevada and the Transverse Ranges.  The Sierra Nevada mountain yellow-legged frog (Rana sierrae) is native to the northern and central Sierra Nevada.  Though once abundant in their respective habitats, re-surveys of historic locations (PDF) show that 95.2% of R. muscosa and 93.3% of R. sierrae populations are locally extinct.  Now that the Commission has declared the mountain yellow-legged frog a candidate species, the Department of Fish and Game must submit a written report within one year indicating whether listing the species is warranted.