On 27 September 1974 we collected a male Black-throated Blue Warbler (Dendroica caerulescens) in immature plumage at the headquarters of the Desert Experimental Range (1,601 m elev.) in Millard Co., Utah, 75.6 km west of Milford. The specimen (No. 5369, Brigham Young Univ. Life Science Museum, Provo, Utah) weighed 10 g. It was assigned to the race caerulescens by Mrs. Roxie C. Laybourne of the National Fish and Wildlife Laboratory, U.S. National Museum. All but the frontal portions of the bird’s skull were 2-layered and pneumatized.