California red-legged frogs (Rana aurora draytonii) have benefited from the reduction of grazing in the watershed.
This improves the quality of grasslands near the alkali marshes and stock ponds, which are breeding areas for this amphibian.
In the summer, when adult red-legged frogs seek shelter, there is little natural vegetation in the area. The District planted willows to create new red-legged frog habitat
The California red-legged frog is the largest frog west of the Continental Divide. It was often offered in restaurants in San Francisco and Central Valley in the early 1900s. Its numbers have plummeted to near extinction in recent decades and it has been listed on the Federal Endangered Species Act since 1996.
The frog is also thought to be the species who's high flying antics are described in Mark Twain's famous story, The Celebrated Jumping Frog of Calaveras County.