A systematic archaeological survey documents prehistoric masonry sites across southwestern Colorado and nearby canyons, cataloguing village plans, cliff dwellings, towers, and defensive works. The author classifies ruins by layout and construction, supplies measured ground plans and photographic plates, and examines masonry techniques, tower construction, reservoirs, cemeteries, pictographs, and minor artifacts. Individual groups receive detailed descriptions and maps, and comparisons emphasize architectural variation—rectangular room blocks, circular ritual or storage compartments, peripheral chambers, and isolated towers. The account concludes by synthesizing site distribution, building practices, and functional interpretations to illuminate past settlement patterns and material culture.