Room 90W is located directly south of Room 89W, in the northeast sector of Salmon Pueblo. The room was originally built during the Chacoan construction episode around 1090, with perhaps some repairs or upper-story construction at 1094. A total of 26 strata was identified in Room 90W, including post-occupational fill, structured trash, roof-fall, occupational fill, floor and floor contact debris, artificial fill, construction debris, and feature fill. There was a mixed Chacoan and San Juan trash deposit separating the two periods of use. Thirty-three features were associated with Room 90W. Chacoan features included three doorways (in the west, north, and south walls), vent windows, a hearth, three pits of unknown purpose, and a large series of vigas from the roof. San Juan features include a burial and an adobe-lined pit. The location of 90W in the second to last tier of rooms at Salmon suggests that it served primarily as a storage room but the presence of a hearth feature may signal some habitation use. Tree-ring dates from Room 90W indicate initial construction during the 1090 episode by the Chacoans. The room was probably used by San Juan residents until the 1280s.