Room 91C is the western third of the subdivided Room 91W that measures 3.6 x 1.8 m. The room was created and used between the mid-1100s and the late 1200s by the San Juan occupants. Nine strata were defined in Room 91C, including post-occupational layers, roof-fall, and floor units. A metate, a mano, other ground stone, and lithic artifacts were associated with the floor unit. Six features were recorded in the room including four narrow wall slots, a door step, and a wall niche. Based on architecture, stratigraphy, and ceramic assemblage, construction and use occurred between the mid 1100s and late 1200s.