Current knowledge of the breeding range, dispersal routes, and wintering range of the Yellow-billed Loon (Gavia adamsii) is summarized by Burn and Mather (1974). However, neither these authors nor the AOU Check-list (1957) cite acceptable records for Mexico or the contiguous western United States. The purpose of this paper is to enumerate and analyze the 52 records that have been obtained from this area during the last 19 years. The problems of distinguishing this species from the Common Loon (Gavia immer) in the field and hand are discussed by Binford and Remsen (1974) and Burn and Mather (1974).