112 CASA GRANDE, ARIZONA [BrH. ANN. 28 
from which was obtained the caliche of which the buildings are 
made. One or two of the depressions are so situated with respect 
to the largest buildings that the adobe of which the houses were built 
may have been carried at times a considerable distance. 
Similar areas inclosed by artificial circular ridges of earth are found 
in several of the clusters of mounds in the Gila and Salt River 
Valleys, among which may be mentioned the one inthe group near 
Adamsville and the reservoir at Casa Blanca. The Escalante Group, 
situated near the Phoenix-Florence Railroad, also contains a similar 
reservoir. In the country south of the Southern Pacific Railroad, 
inhabited by a group of Indians of Piman stock called the Qua- 
hatika (Xwahadt), similarly shaped depressions are recorded, some 
of which are still used as reservoirs at certain seasons. This is like- 
wise true of so-called Indian tanks (Pima, vashki), to the east of Casa 
Grande, near the Santa Catalina Mountains, and elsewhere (pl. 38). 
Certain areas marked by no mounds or depressions may have 
served as race courses or dance places, the existence of which is men- 
tioned in legendary accounts of Casa Grande. 
On the southwest side of the large reservoir is a depression from 
which were obtained the sand and earth out of which walls were 
made, and a similar depression on the east side may have been due 
to a similar cause. There are depressions in the surface near Clan- 
house 1 and Compound D, and those near the western clan-houses ! 
served the same purpose. 
From remains of ancient irrigating ditches in the neighborhood of 
the several compounds it is evident that water from the Gila River 
was conducted over the plain west of Casa Grande. Here and 
there, especially near the large mounds, occur numerous depressions 
in the earth’s surface, some of which are possibly reservoirs, or places 
where the water was stored for irrigation, drinking, and other purposes. 
Most of these depressions are surrounded by a ridge of earth, by which 
their capacity was increased and the chance of overflow diminished. 
Their prevailing shape is oval. The indications are that they have 
been filled to a considerable extent with drifting sand since Casa 
Grande was deserted.? The largest is situated about midway of a 
line extending from the northwest corner of Compound A to the south- 
east corner of Compound C. It was supposed that this reservoir was 
lined with a cement wall, but a section exposed through the rim on the 
south side, which was solid sand throughout, revealed no such condi- 
tion. It is interesting to note that the floor of this reservoir is now 
thickly overgrown with trees and bushes, although without water. 
1 There are mounds west of Compound A, which are here referred to as ‘‘ western clan-houses,” but these 
were not excavated, although traces of caliche walls were found in them. Potsherds were abundant. 
2 Many of the casas grandes in the Gila-Salt region have similar reservoirs, or circular depressions with 
raised rims. Cushing’s excavation of one of these depressions convinced him that it was not a reservoir 
but a ceremonial chamber. 
