On 10 August 2005, a Mount Lyell shrew (Sorex lyelli) was collected at 3,630 m elevation in Humphreys Basin, John Muir Wilderness Area, Fresno County, California. This specimen extends the known range of S. lyelli to the south by 55 km, increases its upper elevational range by ca. 500 m, and is the first alpine record. Prior to our finding, S. lyelli had been collected only in Mariposa, Mono, and Tuolomne counties, at elevations of 2,100–3,156 m, typically in sub-alpine herbaceous vegetation along fast-running streams associated with riparian shrubs, and less frequently in thickets of sub-alpine sagebrush. This record is from an alpine lakeshore well above treeline, with vegetation limited to sedges, grasses, and forbs. This specimen represents the highest elevational record for Sorex in the Sierra Nevada of California.