Scattered about the area shown on the map there are several small
depressions, usually more regular in outline than those described. The
best example is situated near the northeastern corner of the area. It is
situated in the point of a low promontory, is about 3 feet deep, almost
regularly oval in outline, and measures about 50 by 100 feet. A similar
depression less than 2 feet deep occurs near the northwest corner of the
area, and immediately south of the last there is another, more irregular
in outline, and nearly 3 feet deep. There are also some small
depressions in the immediate vicinity of the Casa Grande ruin and of the
mounds north of it.

With a single exception none of these depressions are so situated that
they could be used as reservoirs for the storage of water collected from
the surface, and the catchment area of the depressions is so small and
the rate of evaporation in this area so great that their use as
reservoirs is out of the question. It is probable that all of the
smaller depressions represent simply sites where building material was
obtained. Possibly the ground at these points furnished more suitable
material than elsewhere, and, if so, the builders may have taken the
trouble to transport it several hundred yards rather than follow the
usual practice of using material within a few feet of the site. This
hypothesis would explain the large size of the depressions, otherwise an
anomalous feature.


CASA GRANDE RUIN.

_State of Preservation._