The range of the mountain yellow-legged frog is restricted to montane regions of California and adjacent Nevada. Throughout this range, mountain yellow-legged frogs historically were found in lakes, ponds, marshes, meadows, and streams at elevations of 4,500-12,000 feet (1,370-3,660 m), and often existed at remarkably high densities.
Rana sierrae was found from the Diamond Mountains (Plumas County, California) in the north, and south through the Sierra Nevada. On the west side of the Sierra Nevada, the southern limit of its range is the divide between the Middle Fork and South Fork of the Kings River (Monarch Divide, Cirque Crest, Mather Pass). On the east side of the Sierra Nevada, R. sierrae was found at least as far south as Independence Creek. R. sierrae occurred east of the Sierra Nevada at only a few localities, including a population on Mt. Rose (Nevada) and in the Glass Mountains south-east of Mono Lake (California). There are also reports that R. sierrae populations existed in the White Mountains (on the California-Nevada border) and in Fish Lake Valley (Nevada).
Rana muscosa was found from the southern Sierra Nevada to the Transverse and Peninsular Ranges in southern California. In the Sierra Nevada, R. muscosa occurred from the divide between the Middle Fork and South Fork of the Kings River (Monarch Divide, Cirque Crest, Mather Pass) south to at least Taylor Meadow in southern Tulare County. All known Sierran localities are on the west slope. An isolated population was present on Breckenridge Mountain in Kern County. In the Transverse and Peninsular Ranges, populations were found in the San Gabriel, San Bernardino, and San Jacinto Mountains, and on Palomar Mountain. In these ranges, R. muscosa was found primarily in fast-flowing streams.