On April 25, 2013, the U.S. Fish and Wildlife Service (Service) published a proposed rule (pdf) to list the Sierra Nevada yellow-legged frog (Rana sierrae) as endangered, the northern distinct population segment (DPS) of the mountain yellow-legged frog (Rana muscosa) as endangered, and the Yosemite toad (Anaxyrus canorus) as threatened under the Endangered Species Act (ESA).

According to the Service, populations of the Sierra Nevada yellow-legged frog and the northern DPS of the mountain yellow-legged frog are declining due to habitat degradation and fragmentation, predation, disease, climate change, and other factors impacting the species’ vitality. The Service also determined that Yosemite toad populations are likely to decrease due to habitat degradation and anticipated effects of climate change.

In addition to the proposed listing, the Service also published a proposed rule (pdf) to designate critical habitat for the three species. Specifically, the Service proposed designating over 1.1 million acres of critical habitat for the Sierra Nevada yellow-legged frog, over 200,000 acres for the northern DPS of the mountain yellow-legged frog, and over 750,000 acres for the Yosemite toad. The critical habitat designations include acreage in seventeen counties across California, ranging from Tulare County in the south to Butte County in the north.

Comments regarding either proposed rule must be submitted by June 10, 2013.