Collected by Gervis W. Hoofnagle while he was employed by the U.S. Fish and Wildlife Service from the early 1920s to 1948. While working in southwestern Colorado, Hoofnagle purchased this mug from &quot;an old-timer in Mancos, CO.&quot; The old-timer told Hoofnagle he had collected the mug from a ruin around Mesa Verde.    Black-on-white ceramics were common in the northern San Juan Plateau from the Basketmaker III period until the Pueblo III period (500 AD to 1300 AD). Around 1250 AD the Ancestral…