On September 16, 2019, SDZG researchers achieved a major conservation milestone, releasing more than 260 endangered mountain yellow-legged frog adults and froglets and more than 680 tadpoles into the San Bernardino and San Jacinto Mountains. Working with U.S. Geological Survey (USGS) and other partners, the research team implanted radio-telemetry transmitters into a group of the adult frogs, the first time transmitters had been used to track these frog populations during their annual hibernation cycle. The data collected from the trackers would provide them with much-needed information, such as how the frogs use their habitat and the locations they choose as hibernation sites.