VI. Report of the Director of the Bureau of American Ethnology to the Secretary of the Interior on the examination of the condition of Casa Grande by Mr W J McGee, with a recommendation concerning its further protection

  Smithsonian Institution,
      Bureau of American Ethnology,
          Washington, November 15, 1895.

Sir:  Pursuant to a proposal made in connection with a report from this office relating to the ruins known as Casa Grande, near Florence, Arizona, under date of August 28, 1895, and to the acceptance of this proposal in a communication from the Department of the Interior under date of September 12, 1895, Mr W J McGee, ethnologist in charge of the Bureau of American Ethnology, has within a few days made an examination of Casa Grande ruin with the view of determining the need for further protection of the ruin by a roof or otherwise.

There are in this office two series of photographs representing the ruin.  The first series was taken in 1892 before the protective works authorized by the Congress were commenced; the second series represents the work in progress.  In the recent examination the present condition of the ruin was carefully compared with the condition represented in the photographs.

On comparing the profiles of the walls, it was found that in many cases the irregular upper surfaces retain the exact configuration of 1892, even to the slightest knobs and rain-formed crevices; the correspondence being so close as to show that the injury and loss by weathering during the interim has been imperceptible.  In some other cases, notably along the southern and eastern walls, the profiles are more extensively modified; some of the points and knobs shown in the photographs are gone, some of the old crevices are widened and deepened, and some new crevices appear; and in some parts it can be seen that walls are lowered several inches.  On the whole the modification of the profiles of the walls is limited, yet such as to indicate that destruction is proceeding at a not inconsiderable rate.

On comparing the scars and crevices on the sides of the walls, it was found that, while many remain essentially unchanged, most are enlarged and deepened.  This is particularly noteworthy on the eastern and southern walls, which are most beaten by wind-driven rains, and which are also most modified in profile.  It would appear that destruction is proceeding more rapidly along the sides of the walls than along the crests.

On examining the walls with respect to apparent solidity and stability, it was found that nearly all are in fair or good condition.  The only portion that would seem in special danger is the central section of the southern exterior wall.  This section seems insecure, and might at any time be overthrown by a heavy wind following a rain storm.  This section was not, unfortunately, braced or tied