Resident and breeding Acorn Woodpeckers (Melanerpes formicivorus) were first found on the east side of the Sierra Nevada in Lassen County, California, in 1959 (McKeever and Adams 1960). Currently, that area is the only published site of breeding and residence of this species in the eastern Sierra. In Inyo County, California, approximately 416 km south of Lassen County, the Acorn Woodpecker has been considered a regular vagrant and possible resident (Garrett and Dunn 1981, Small 1994), but long-term residence and breeding have never been confirmed. Here we provide evidence of Acorn Woodpecker residence in native oak (Quercus) habitats near Independence, Inyo County, as well as the first county breeding records for the species.