The mountain yellow-legged frog (MYLF) is a federal and California state endangered species. The southern California Distinct Population Segment (DPS) of the southern mountain yellow-legged frog (Rana muscosa) is endemic to the southern Sierra Nevada and Transverse Ranges. Within the San Gabriel Mountains, the upper segment of Little Rock Creek supports the largest MYLF population remaining in southern California and is a designated Critical Habitat. Population numbers declined considerably due to nonnative trout predation and habitat impacts. Since 2012, the California Department of Transportation (Caltrans) funded mitigation to restore this critical site. Winter storms in December 2010 washed out the roadway support slope (10,000 cubic yards of material) and sections of the southbound roadway. The storms also dislodged the drainage system and metal beam guard rail along State Route 2 at Post Mile 61.5 in the vicinity of Eagles Roost picnic area within the Angeles National Forest (ANF). Caltrans initiated emergency repairs, and on July 7, 2011, debris and sediment were observed in Little Rock Creek, downslope of the project site. Caltrans Division of Environmental Planning Biologists and Division of Maintenance determined that the cost of satisfying the entire mitigation would total $776,000 ($475,000 to USGS and $301,000 to USFS). A cooperative agreement was executed in 2012—funds were transferred, and mitigation was implemented successfully. Through this mitigation, United States Geological Survey (USGS) was able to monitor the site for several years, which allowed for real-time identification of threats and population status. This triggered specific conservation actions to increase population numbers, such as breeding MYLF and translocating tadpoles from Little Rock Creek to other creeks within their historic footprint. From September 6 to November 2, 2020, the Bobcat Fire burned 115,796 acres of the ANF, including the entire Little Rock Creek watershed. Biologists from the Caltrans surveyed the creek and documented the existing conditions on October 29, 2020. Surrounding vegetation was denuded by the fire, and the creek was filled with ash and debris. To prevent fire generated sediments from further washing downstream, erosion control measures were implemented, and debris catchment elements were repaired during emergency project activities. Due to potential post-fire flooding and debris flows, USGS, in accordance with multi-agency recommendations and coordination, conducted emergency rescue and translocation of MYLF adults from Little Rock Creek to another area of suitable habitat in the San Gabriel Mountain. Tadpoles were collected for placement in captivity and will be integrated into the existing captive breeding and translocation program. On April 2021, USGS biologists noted that Little Rock Creek has returned to its pristine, pre-Bobcat Fire conditions. Surveys will continue to evaluate the effects of this fire on the MYLF.