The methods employed in the construction of the buildings of the Casa
Grande were thoroughly aboriginal and characteristically rude in
application. A fair degree of adaptability to purpose and environment is
seen, indicating that the Casa Grande was one, and not the first,
building of a series constructed by the people who erected it and by
their ancestors, but the degree of skill exhibited and amount of
ingenuity shown in overcoming difficulties do not compare with that
found in many northern ruins. As architects, the inhabitants of the Casa
Grande did not occupy the first rank among pueblo-builders.

It is probable that the Casa Grande ruin as we see it today shows very
nearly the full height of the structure as it stood when it was
abandoned. The middle tier of rooms rose to a height of three stories;
the others were but two stories high. It is also probable that the
building was enlarged after being once completed and occupied. At one
time it probably consisted of four rooms on the ground plan, each two
stories high. The northern tier, of rooms was added afterward, and
probably also the third room in the central tier.

The Casa Grande was undoubtedly built and occupied by a branch of the
Pueblo race, or by an allied people. Who these people were it is
impossible to determine finally from the examination of one ruin, but
all the evidence at hand suggests that they were the ancestors of the
present Pima Indians, now found in the vicinity and known to have
formerly been a pueblo-building tribe. This conclusion is supported by
the Pima traditions, as collected by Mr. Bandelier, who is intimately
acquainted with the documentary history of the southwest, and whose
knowledge of the Pima traditions is perhaps greater than that of anyone
else now living. In his various writings he hints at this connection,