At the Sun Dagger site, three sandstone slabs cast precise markings in shadow and light onto two spiral petroglyphs behind them. These markings correspond to the yearly cycles of the sun and the cycles of the moon. This model is now displayed with interactive tools in the New Mexico Museum of Natural History in Albuquerque, NM.
Photogrammetric measurements, collected at the site in 1984, were integrated in 2005 with GPS and LiDAR data, to create the interactive computer model. More information regarding how this model was developed, in partnership with Alan Price of OSU, can be found in Anna Sofaer’s book Chaco Astronomy.