Yosemite National Park is restoring the federally endangered Sierra Nevada yellow-legged frog to alpine lakes within the park. The yellow-legged frog was once the most common frog in mountain lakes throughout the Sierra Nevada, but introduced predators and diseases caused their population to decline by over 95 percent. Park experts are encouraged by the results of initial restoration efforts and estimate that the population in Yosemite could become self-sustaining within the next ten years. http://www.nps.gov/yose/learn/news/frogrestoration.htm