The magnitude of this building project, without an apparent utilitarian purpose, indicates that Fajada Butte may have had considerable ceremonial importance for the Chacoan people.

on the summer solstice a dagger-shaped light form pierces the larger of the two spirals (Sofaer, Zinser and Sinclair 1979, p. 285).

Due to one of the slabs settling, the "dagger of light" no longer crosses through the center of the spiral during the summer solstice.

[5] Public access to the butte was curtailed when, in 1989, erosion from modern foot traffic was found to be responsible for one of the three screening slabs at the "Sun Dagger" site shifting out of its ancient position.

In the 1980s the National Park Service closed off access to the butte due to the delicate nature of the site and the damage and erosion caused by tourism.

Critics generally agree that the light and shadow phenomena at the site were intended to mark the arrival of the sun at the solstices and equinoxes (Carlson 1987, pp.