Room 123A is the northern portion of subdivided 123W. It measures 3 x 2.3 m and is divided from 123B by a cobble-and-mortar wall built during the San Juan occupation. The six strata identified in Room 123A consist of post-occupational layers, roof-fall, structured trash, and a floor complex. Room 123A had just one feature - a milling bin. The room evidently functioned as a milling facility, with use for corn storage as well. Based on the architectural style, stratigraphy, and ceramic assemblage, Room 123A was created sometime after 1130 and before 1200.