Casa Grande appears to be the sole surviving remnant of an extensive and
important class of remains in the southwest. These remains occur usually
in large groups or clusters, and Casa Grande is no exception. The name
has been ordinarily applied to a single house structure standing near
the southwestern corner of a large area covered by mounds and other
debris; but some writers have applied the term to the southwestern
portion of the area, others to the whole area.
Probably no two investigators would assign exactly the same limits to
this area, as its margins merge imperceptibly into the surrounding
country. The accompanying map (plate CXII) shows the limits of the ruins
as interpreted by the writer. The surface covered by well-defined
remains, as there shown, extends about 1,800 feet north and south and
1,500 feet east and west, or a total area of about 65 acres.
Casa Grande ruin occupies a position near the southwestern corner of the
group, and its size is insignificant as compared with the entire cluster
of ruins, or even with the remains of the large structure which occupied
the north-central part of the area. The contour interval on the map is 1
foot, sufficiently small to show much surface detail. The depressions
are indicated by dotted contours.
Within the area shown on the map there are a large number of mounds,
more or less leveled by long-continued exposure to the elements. Some
appear to be quite old, others represent buildings which were standing
within the historic period, and many interesting features are presented
which can not even be alluded to here.
Casa Grande proper was one of the smallest of the house clusters, but it
is unique in that the walls are still standing to a height of more than
25 feet. While fragments of standing wall are not uncommon, either in
the area mentioned or in the valleys of Gala and Salt rivers generally,
no other example exists, so far as known, so well preserved as the one
under consideration.
For miles around Casa Grande the ground surface is so flat that from the
summit of the walls an immense stretch of country is brought under view
in every direction. In the whole southwest, where there are thousands of
ruins, many of which represent villages located with especial reference
to outlook, there are few, if any, so well situated as this.
A ground plan of the ruin is shown in plate CXII and a general view in
plate CXIV. The area covered and inclosed by standing walls is about 43
by 59 feet, but the building is not exactly rectangular, nor do its
sides exactly face the cardinal points, notwithstanding many published
statements to that effect. The building comprised three central rooms,
each approximately 10 by 24 feet, arranged side by side with the longer
axes north and south, and two other rooms, each about 9 by 35 feet,
occupying, respectively, the northern and southern ends of the building,
and arranged transversely across the ends of the central rooms, the
longer axes running east and west. Excepting the central tier of rooms,
which was three stories high, all the walls rose to a height of two
stories above the ground. The northeastern and southeastern corners of
the structure have fallen, and large blocks of the material of which
they were composed are strewn upon the ground in the vicinity.
The exterior walls rise to a height of from 20 to 25 feet above the
ground. This height accommodated two stories, but the top of the wall is
from 1 to 2 feet higher than the roof level of the second story. The
middle room or space was built up three stories high, and the walls are
still standing to a height of 28 to 30 feet above the ground level. The
tops of the walls, while rough and greatly eroded, are approximately
level. The exterior surface of the walls is rough, as shown in the
illustrations, but the interior walls of the rooms are finished with a
remarkable degree of smoothness, so much so that it has attracted the
attention of everyone who has visited the ruin. Plate CXV shows this
feature. At the ground level the exterior wall is from 3½ to 4½ feet
thick, and in one place over 5 feet thick. The interior walls are from 3
to 4 feet thick. At the tops the walls are about 2 feet thick. The
building was constructed by crude methods, thoroughly aboriginal in
character, and there is no uniformity in its measurements. The walls,
even in the same room, are not of even thickness; the floor joists were
seldom in a straight line, and measurements made at similar places (for
example, at the two ends of a room) seldom agree.
Casa Grande is often referred to as an adobe structure, but this use of
the term is misleading. Adobe construction consists of the use of molded
brick, dried in the sun, but not baked. The walls here are composed of
huge blocks of rammed earth, 3 to 5 feet long, 2 feet high and 3 to 4
feet thick. These blocks were not molded and then laid in the wall, but
were manufactured in place.
Plate CXVI shows the character of these blocks. The material employed
was admirably suited for the purpose, being when dry almost as hard as
sandstone and nearly as durable. A building with walls of this material
would last indefinitely, provided a few slight repairs were made at the
conclusion of each rainy season. When abandoned, however, sapping at the
ground level would commence and would in time bring down all the walls;
yet in the two centuries which have elapsed since Padre Kino's visit to
this place--and Casa Grande was then a ruin--there has been but little
destruction from the elements, the damage done by relic hunters during
the last twenty years being, in fact, much greater than that due to all
causes in the preceding two centuries.
The building was well provided with doorways and other openings,
arranged in pairs, one above the other. There were doorways from each
room into every adjoining room, except that the rooms of the middle tier
were entered only from the east. Some of the openings were not used, and
were closed with blocks of solid masonry, built into them long prior to
the final abandonment of the structure.