Room 1W comprises two subunits, 1W and 2W. The larger Chacoan era room was initially defined as 1W. Once the San Juan subdividing wall was encountered, excavators retained the name 1W for the east half and designated the west half as 2W. 1W is located in the southwest sector of Salmon Pueblo and measures 3.6 x 3.3 m. Nineteen strata were designated. Four separate floor units were identified, along with fill sequences, structured trash deposits, and roof-fall strata. Two, possibly three, Chacoan floors were present in 1W. Six features were discovered in Room 1W. Because Rooms 1W, 2W, and 5W do not follow the typical Chacoan room suite pattern and were built at the end of the west wing, they appear to represent an add-on to the original design. A later, partial San Juan period burial was placed into the Chacoan deposits of this room. No tree-ring dates comes from Room 1W but its masonry style and ceramics indicate construction during the Chacoan interval.