114 CASA GRANDE, ARIZONA [BTH. ANN. 28 
tered throughout its entire course. The canal-divided probably 
shortly after it left the river, sending a branch that runs east of 
Clan-house 1 to supply the fields on the east side of the compounds. 
From the point of bifurcation the remains of a smaller canal can be 
traced for some distance. 
As above stated there is evidence that buildings once stood on the 
banks of these ditches, where their former presence is now indicated 
by low mounds on which are scattered fragments of pottery and a-few 
broken stone implements (metates, or grinders). Irrigation ditches 
are more apparent elsewhere in the Gila and Salt River Valleys than 
at Casa Grande. The settlement near Poston Butte was supplied 
with water by one of the best-preserved of these ancient ditches in 
the Gila-Salt Valley. This follows the right bank of the Gila from a 
point several miles higher up the river and extends to the neighbor- 
hood of the Escalante ruin, where it is lost in laterals or minor. 
branches. Near Poston Butte, the southern side of which it skirts, 
the banks of this prehistoric ditch are head high and can be traced 
for many hundred feet without difficulty. The writer has been in- 
formed by an old Mexican who lives in Florence that when a boy he 
saw stumps of old logs in this ditch at the point where the banks are 
highest; he believes these were remains of a prehistoric head-gate. 
In the following quotation H. C. Hodge refers to a prehistoric irri- 
gation ditch on the north side of the Gila near Poston Butte:! 
About 2 miles west of Florence, on the north side of the river, between the homes of 
Mr. Stiles and Mr. Long, is a stretch of hard, stony land, through which another of 
the large irrigating canals was cut, and where, for several hundred yards, one can ride 
on horseback in the canal, which is yet so deep one can not look over its banks on 
either side, when sitting on his horse. 
Some of the best irrigating ditches in the Gila-Salt Valley were 
found near Phoenix and Mesa when the country was first en- 
tered by Americans. That near Mesa was utilized by the Mormon 
farmers who settled this region; others have been filled or destroyed 
by modern agriculture. The lines of many of thé new ditches fol- 
low substantially the lines of the prehistoric canals, showing the 
skill of the primitive farmers. The irrigation ditches in the neigh- 
borhood of Phoenix have been traced and mapped by Mr. H. R. 
Patrick,? under whose guidance the writer has visited certain remains 
still visible near that city. These can now be traced only at inter- 
vals, and in many instances nothing remains but ridges of earth or 
rows of stones. 
It appears from Mr. F. H. Cushing’s studies of the irrigation ditches? 
near the ruins of Los Muertos in the Salt River Valley that some 
1 Arizona As It Is; or, The Coming Country, p. 182, Boston, 1877. 
2 The Ancient Canal Systems and Pueblos of the Salt River Valley, Arizona, Phoenix, Ariz., 1903. 
*See F. W. Hodge, in American Anthropologist, V1, 323, Washington, 1893. 
