38 CASA GRANDE, ARIZONA [BTH. ANN. 28 
level, no sign of the boundary wall of the compound projecting 
above the surrounding plain. 
On excavating to the base of the western, or outermost, of the two 
fragments it was discovered that the true foundations are deep below 
the eroded part and that a thick wall extends north and south from 
that point. This wall was found to continue to a point 420 feet to 
the north, where it turns at right angles, forming the northwest 
corner of the compound, thence running 230 feet in an easterly 
direction. Thus was brought to ight the west wall, the longest wall 
of any compound in the Casa Grande Group of ruins. It was then a 
simple task to trace the three remaining walls, those forming the 
north, south, and east sides of the compound. \ (PI. 6.) 
After the surrounding walls of Compound A had been traced 
throughout their whole length by excavation, a trench being dug 
along the outside of each to its foundations, it was necessary to 
remove the earth that had accumulated without and within the 
inclosure through the years that had passed since Compound A had 
been abandoned. This was an undertaking of magnitude. When 
Casa Grande was inhabited the wall of the compound was probably 
7 feet high. The upper part (about 3 feet) had fallen level with the 
ground, about 4 feet above the base, and the débris had filled in 
along the base throughout the whole length and breadth of the 
compound.' This great accumulation of clayey soil was removed by 
means of scrapers and transported to the distance of about 50 feet 
from the compound. 
In addition to the removal of the earth that had fallen outside the 
compound,’ on the four sides, a drain was dug from the base of each 
wall along its entire length. This was constructed with sufficient 
incline to convey water from the wall into a larger ditch extending 
from the northeast corner to a depression 200 feet away. Similar 
removals of earth were made and similar ditches constructed on all 
sides of Compound A; the aggregate length of the drains thus made 
about this compound is not far from 1,500 feet. 
The construction of the main drainage ditch just mentioned was 
a work of considerable magnitude, as it was necessary, in order to 
insure the requisite fall, to cut through several elevations or refuse- 
heaps, that obstructed the course. In addition to the draining 
ditches above described, a layer of clay coated with a thin layer of 
cement was placed along the bases of the walls of Compound A to 
prevent undermining and rapid destruction of their foundations; in 
some places Mexican adobes were laid on top of the wall to shed 
water and preserve it from erosion. The foundations of the walls 
1A preliminary report on the excavations made in 1906-7 was published in Smithsonian Miscellaneous 
Collections, L (No. 1772), 1907. E 
2 The accumulation of earth on the east side near the southeast angle was not removed. It is conjectured 
that this part of the compound was once occupied by small huts, the habitations of the people. 
