One of the finest examples of an aboriginal irrigating ditch that has
come under the writer’s notice occurs about 2 miles below the mouth of
Limestone creek, on the opposite or eastern side of the river. At this
point there is a large area of fertile bottom land, now occupied by some
half dozen ranches, known locally as the Lower Verde settlement. The
ditch extends across the northern and western part of this area. Plate
XXXIV shows a portion of this ditch at a point about one eighth of a
mile east of the river. Here the ditch is marked by a very shallow
trough in the grass-covered bottom, bounded on either side by a low
ridge of earth and pebbles. Plate XXXV shows the same ditch at a point
about one-eighth of a mile above the last, where it was necessary to cut
through a low ridge. North of this point the ditch can not be traced,
but here it is about 40 feet above the river and about 10 feet above a
modern (American) ditch. It is probable that the water was taken out of
the river about 2 miles above this place, but the ditch was run on the
sloping side of the mesa which has been recently washed out. No traces
of the ditch were found east of the point shown in plate XXXIV, but as
the modern acequia, which enters the valley nearly 10 feet below the
ancient one, extends up the valley nearly to its head, there is no
reason to suppose that the ancient ditch did not irrigate nearly the
whole area of bottom land. The ancient ditch is well marked by two
clearly defined lines of pebbles and small bowlders, as shown in the
illustration. Probably these pebbles entered into its construction, as
the modern ditch, washed out at its head and abandoned more than a year
ago, shows no trace, of a similar marking.
[Illustration: Figure 299.
Map of an ancient irrigating ditch.]
A little west and south of the point shown in plate XXXIV the bottom
land drops off by a low bench of 3 or 4 feet to a lower level or
terrace, and this edge is marked for a distance of about a quarter of a
mile by the remains of a stone wall or other analogous structure. This
is located on the extreme edge of the upper bench and it is marked on
its higher side by a very small elevation. On the outer or lower side it
is more clearly visible, as the stones of which the wall was composed
are scattered over the slope marking the edge of the upper bench. At
irregular intervals along the wall there are distinct rectangular areas
about the size of an ordinary pueblo room, i.e., about 8 by 10 and 10 by
12 feet.
In February, 1891, there was an exceptional flood in Verde river due to
prolonged hard rain. The river in some places rose nearly 20 feet, and
at many points washed away its banks and changed the channel. The river
rose on two occasions; during its first rise it cut away a considerable
section of the bank near a point known as Spanish wash, about 3½ miles
below Verde, exposing an ancient ditch. During its second rise it cut
away still more of the bank and part of the ancient ditch exposed a few
days before. The river here makes a sharp bend and flows a little north
of east. The modern American ditch, which supplied all the bottom lands
of the Verde west of the river, was ruined in this vicinity by the flood
that uncovered the old ditch. Figure 299 is a map of the ancient ditch
drawn in the field, with contours a foot apart, and showing also a
section, on a somewhat larger scale, drawn through the points _A_, _B_
on the map. Plate XXXVI is a view of the ditch looking westward across
the point where it has been washed away, and plate XXXVII shows the
eastern portion, where the ditch disappears under the bluff.
The bank of the river at this point consists of a low sandy beach, from
10 to 50 feet wide, limited on the south by a vertical bluff 10 to 12
feet high and composed of sandy alluvial soil. This bluff is the edge of
the bottom land before referred to, and on top is almost flat and
covered with a growth of mesquite, some of the trees reaching a diameter
of more than 3 inches. The American ditch, which is shown on the map,
runs along the top of the bluff skirting its edge, and is about 14 feet
above the river at its ordinary stage. The edge of the bluff is shown on
the map by a heavy black line. It will be observed that the ancient
ditch occurs on the lower flat, about 3 feet above the river at its
ordinary stage, and its remains extend over nearly 500 feet. The line,
however, is not a straight one, but has several decided bends. One of
these occurs at a point just west of that shown in the section. About 80
feet east of that point the ditch makes another turn southward, and
about 40 feet beyond strikes the face of the bluff almost at right
angles and passes under it.
About 50 feet north of the main ditch, at the point where it passes
under the bluff, there are the remains of another ditch, as shown on the
map. This second ditch was about a foot higher than the main structure,
or about 4 feet above the river; it runs nearly parallel with it for 30
feet and then passes into the bluff with a slight turn toward the north.
It is about the same size as the main ditch, but its section is more
evenly rounded. Figure 300 shows this ditch in section.
[Illustration: Plate XXXIX.
ANCIENT DITCH AND HORTICULTURAL WORKS ON CLEAR CREEK.]
As already stated, the American ditch is about 14 feet above the river,
while the ancient ditch is less than 4 feet above the water. This
decided difference in level indicates a marked difference in the
character of the river. The destruction of the modern ditch by the flood
of 1891 is not the first mishap of that kind which has befallen the
settlers. The ditch immediately preceding the current one passed nearly
over the center of the ancient ditch, then covered by 10 feet or more of
alluvial soil, and if a ditch were placed today on the level of the
ancient structure it would certainly be destroyed every spring. The
water that flowed through the modern ditch was taken from the river at a
point about 3 miles farther northward, or just below Verde. The water
for the ancient ditch must have been taken out less than a mile above
the southern end of the section shown in the map.
[Illustration: Figure 300.
Part of old irrigating ditch.]
At first sight it would appear that the ancient ditch antedated the
deposit of alluvial soil forming the bottom land at this point, and this
hypothesis is supported by several facts of importance. It is said that
ten years ago the bottom land, whose edge now forms the bluff referred
to, extended some 25 or 30 feet farther out, and that the river then
flowed in a channel some 200 or 300 feet north of the present one.
Be this as it may, the bottom land now presents a fairly continuous
surface, from the banks of the river to the foothills that limit the
valley on the west and south, and it is certain that this bottom land
extended over the place occupied by the ancient ditch; nor is it to be
supposed that the ancient ditches ended abruptly at the point where they
now enter the bluff. The curves in the line of the ancient ditch might
indicate that it was constructed along the slope of a hill, or on an
uneven surface, as a deep excavation in fairly even ground would
naturally be made in a straight line.
The face of the bluff shows an even deposit of sand, without apparent
stratification, except here and there a thin layer or facing of mud
occurs, such as covers the bottom of the ancient ditch and also of the
modern ditch. Singularly enough, however, over the ancient ditch, about
5 feet above its bottom, there is a stratum of sand and gravel, and on
top, within a few inches of the surface of the ground, a thin stratum of
mud. This mud stratum extends only about 8 feet horizontally and is
slightly hollowed, with its lowest part over the center of the ditch.
The gravel stratum also was laid down over the ditch, is tilted slightly
southward and occurs in two layers, together about a foot thick. It
first appears a few feet south of the point where the main ditch enters
the bluff and over the ditch both layers are distinctly marked, as shown
in plate XXXVIII. Both layers are clearly marked to a distance of 4 feet
north of the northern side of the main ditch; here the lower layer thins
out, but the upper layer continues faintly marked almost to the edge of
the small ditch. At this point the gravel stratum becomes pronounced
again and continues over the small ditch, almost pure gravel in places,
with a decided dip westward. At a point just beyond the northern side of
the small ditch the gravel layer disappears entirely.
The occurrence of this gravel in the way described seems to indicate
that the ditch was built along the slope of a low hill forming the edge
of the bottom land at that time, and that subsequently detritus was
deposited above it and over the adjacent bottom land forming a smooth
ground surface. Against this hypothesis it must be stated that no
evidence whatever was found of more than a single deposit of sandy loam,
although the exposures are good; but perhaps were an examination made by
a competent geologist some such evidence might be developed.
[Illustration: Plate XL.
ANCIENT DITCH AROUND A KNOLL, CLEAR CREEK.]
There is one fact that should not be lost sight of in the discussion,
viz, the very low elevation of the ditch above the river. The Verde is,
as already stated, a typical mountain stream, with an exceptionally high
declivity, and consequently it is rapidly lowering its bed. If, as
already conjectured, the water for the ancient ditch was taken from the
river but a short distance above the point where remains of the ditch
are now found--and this assumption seems well supported by the character
of the adjacent topography--the slight elevation of the bed of the ditch
above the river would indicate that, in the first place, the ditch was
located, as already suggested, along the slope of a hill, and in the
second place, that the ditch was built at a period of no great
antiquity. The occurrence of the high bluff under which the ditch now
passes does not conflict with this suggestion, for the deposition of the
material composing it and its erosion into its present form and
condition may be the result of decades rather than of centuries of work
by a stream like the Verde, and certainly a hundred, or at most a
hundred and fifty years would suffice to accomplish it. At the present
time a few floods deposit an amount of material equal to that under
discussion, and if subsequently the river changed its channel, as it
does at a dozen different points every spring, a few decades only would
be required to cover the surface with grass and bushes, and in short, to
form a bottom land similar to that now existing over the ancient ditch.
In conclusion it should be noted, in support of the hypothesis that the
ditch was built before the material composing the bluff was laid down,
that immediately under the ditch there is a stratum of hard adobe-like
earth, quite different from the sand above it and from the material of
which the bluff is composed. This stratum is shown clearly in plate
XXXVIII.
The hypothesis which accords best with the evidence now in hand is that
which assumes that the ditch was taken out of the river but a short
distance above the point illustrated, and that it was built on the slope
of a low hill, or on a nearly flat undulating bottom land, before the
material composing the present bottom or river terrace was deposited,
and that the ditch, while it may be of considerable antiquity, is not
necessarily more than a hundred or a hundred and fifty years old; in
other words, we may reach a fairly definite determination of its minimum
but not of its maximum antiquity.
On the southern side of Clear creek, about a mile above its mouth, there
are extensive horticultural works covering a large area of the terrace
or river bench. These have already been alluded to in the description of
the village ruin overlooking them, but there are several features which
are worthy a more detailed description. For a distance of 2 miles east
and west along the creek, and perhaps half a mile north and south, there
are traces of former works pertaining to horticulture, including
irrigating ditches, “reservoirs,” farming outlooks, etc.
At the eastern end of these works, about 3 miles above the mouth of
Clear creek, the main ditch, after running along the slope of the hill
for some distance, comes out on top of the mesa or terrace nearly
opposite the Morris place. The water was taken from the creek but a
short distance above, hardly more than half a mile. West of the point
where the ditch comes out on the mesa top, all traces of it disappear,
but they are found again at various points on the terrace. Plate XXXIX
shows a portion of the terrace below and opposite the rectangular ruin
previously described. In the distant foreground the light line indicates
a part of the ancient ditch. Plate XL shows the same ditch at a point
half a mile below the last, where it rounds a knoll. In the distance is
the flat-topped hill or mesa on which the rectangular ruin previously
described is located. About a hundred yards southeast of this point
further traces of the ditch may be seen, and connected with it at that
point are a number of rectangular areas, which were cultivated patches
when the ditch was in use.
The whole surface of the terrace within the limits described is covered
by small water-worn bowlders scattered so thickly over it that travel is
seriously impeded. In many parts of it these bowlders are arranged so as
to inclose small rectangular areas, and these areas are connected with
the old ditch just described. Plate XXXIX shows something of this
surface character; and in the right hand portion of it may be seen some
of the rows of bowlders forming the rectangular areas. The rows which
occur at right angles to the ditch are much more clearly marked than
those parallel to it, and the longer axes of the rectangular areas are
usually also at right angles to the ditch line. On the ground these
traces of inclosures can hardly be made out, but from an elevated point,
such as the mesa on which, the rectangular ruin overlooking these works
is located, they show very clearly and have the appearance of windrows.
Traces of these horticultural works would be more numerous, and
doubtless more distinct, were it not that a considerable part of the
area formerly under cultivation has been picked over by the modern
settlers in this region, and immense quantities of stone have been
removed and used in the construction of fences. This has not been done,
however, in such a manner as to leave the ground entirely bare, yet bare
areas occur here and there over the surface, where doubtless once
existed a part of the general scheme of horticultural works.
One such bare area occurs close to the edge of the terrace about a mile
and a half above the mouth of the creek. In its center is a structure
called for convenience a reservoir, although it is by no means certain
that it was used as such. It occurs about 100 yards from the creek,
opposite the Wingfield place, and consists of a depression surrounded by
an elevated rim. It is oval, measuring 108 feet north and south and 72
feet east and west from rim to rim. The crown of the rim is 5 feet 8
inches above the bottom of the depression and about 3 feet above the
ground outside. The rim is fairly continuous, except at points on the
northern and southern sides, where there are slight depressions, and
these depressions are further marked by extra large bowlders. At its
lowest points, however, the rim is over 2 feet above the ground, which
slopes away from it for some distance in every direction. Plate XLI
shows the eastern side of the depression; the large tree in the middle
distance is on the bank of Clear creek and below the terrace. Plate XLII
shows the northern gateway or dip in the rim, looking southward across
the depression. The large bowlders previously referred to can be clearly
seen. A depression similar to this occurs on the opposite side of the
valley, about half a mile from the river. In this case it is not marked
by bowlders or stones of any description, but is smooth and rounded,
corresponding to the surface of the ground in its vicinity. In the
latter as in the former case, the depression occurs on a low knoll or
swell in the bottom land, and the surface of the ground slopes gently
away from it for some distance in every direction.
[Illustration: Plate XLI.
ANCIENT WORK ON CLEAR CREEK.]
The purpose of these depressions is not at all clear, and although
popularly known as reservoirs it is hardly possible that they were used
as such. The capacity of the Clear creek depression is about 160,000
gallons, or when two-thirds full, which would be the limit of its
working capacity, about 100,000 gallons. The minimum rate of evaporation
in this region in the winter months is over 3 inches per month, rising
in summer to 10 inches or more, so that in winter the loss of water
stored in this depression would be about 10,000 gallons a month, while
in summer it might be as high as 35,000 or even 40,000 gallons a month.
It follows, therefore, that even if the reservoir were filled to its
full working capacity in winter and early spring it would be impossible
to hold the water for more than two months and retain enough at the end
of that time to make storing worth while. It has been already stated,
however, that these depressions are situated on slight knolls and that
the land falls away from them in every direction. As no surface drainage
could be led into them, and as there is no trace on the ground of a
raised ditch discharging into them, they must have been filled, if used
as reservoirs, from the rain which fell within the line that
circumscribes them. The mean annual rainfall (for over seventeen years)
at Verde, a few miles farther northward in the same valley, is 11.44
inches, with a maximum annual fall of 27.27 inches and a minimum of 4.80
inches. The mean annual fall (for over twenty-one years) at Fort
McDowell, near the mouth of the Rio Verde, is 10-54 inches, with a
maximum of 20.0 inches and a minimum of 4.94 inches.[8]
[Footnote 8: Report on Rainfall (Pacific coast and western states
and territories), Signal Office U.S. War Dept., Senate Ex. Doc. 91,
50th Cong., 1st Sess., Washington, 1889; pp. 70-73 (Errata, p. 4).]
If these depressions were used as reservoirs it is a fair presumption
that the bottoms were plastered with clay, so that there would be no
seepage and the only loss would be by evaporation. Yet this loss, in a
dry and windy climate such as that of the region here treated, would be
sufficient to render impracticable a storage reservoir of a cross
section and a site like the one under discussion. Most of the rainfall
is in the winter months, from December to March, and it would require a
fall of over 12 inches during those months to render the reservoir of
any use in June; it would certainly be of no use in July and August,
at the time when water is most needed, save in exceptional years with
rainfall much in excess of the mean.
On the other hand, there is the hypothesis that these depressions
represent house structures; but if so these structures are anomalous in
this region. The contour of the ground does not support the idea of a
cluster of rooms about a central court, nor does the débris bear it out.
Mr. F. H. Cushing has found depressions in the valleys of Salt and Gila
rivers somewhat resembling these in form and measurement, and situated
always on the outskirts of the sites of villages. Excavations were made,
and as the result of these he came to the conclusion that the
depressions were the remains of large council chambers, as the floors
were hard, plastered with mud, and dish-shaped, with a fire-hole in the
center of each; and no pottery or implements or remains of any kind were
found except a number of “sitting stones.” Mr. Cushing found traces of
upright logs which formed the outer wall of the structure; he inferred
from the absence of drainage channels that the structure was roofed, and
as the ordinary method of roofing is impracticable on the scale of these
structures, he supposed that a method similar to that used by the Pima
Indians in roofing their granaries was employed, the roof being of a
flattened dome shape and composed of grass or reeds, formed in a
continuous coil and covered with earth. If the depressions under
discussion, however, are the remains of structures such as these
described, they form a curious anomaly in this region, for, as has been
already stated, the affinities of the remains of this region are with
the northern architectural types, and not at all with those of the
southern.
There is a third hypothesis which, though not supported by direct
evidence, seems plausible. It is that the depression of Clear creek, and
perhaps also the one on the opposite side of the Verde, were thrashing
floors. This hypothesis accords well with the situation of these
depressions upon the tillable bottom lands, and with their relation to
the other remains in their vicinity; and their depth below the surface
of the ground would be accounted for, under the assumption here made of
their use, by the high and almost continuous winds of the summer in this
region. Perhaps the slight depressions at the northern and southern side
of the oval were the gateways through which the animals which trampled
the straw or the men who worked the flails passed in and out. Whether
used in this way or not, these depressions would be, under the
assumption that the bottom was plastered with mud, not only practicable,
but even desirable thrashing floors, as the grain would be subjected
during thrashing to a partial winnowing. This suggestion would also
account for the comparatively clean ground surface about the depressions
and for their location on slightly elevated knolls.
Scattered over the whole area formerly under cultivation along Clear
creek are the remains of small, single rooms, well marked on the ground,
but without any standing wall remaining. These remains are scattered
indiscriminately over the terrace without system or arrangement; they
are sometimes on the flat, sometimes on slight knolls. They number
altogether perhaps forty or fifty. Plate XLIII shows an example which
occurs on a low knoll, shown also in plate XL; it is typical of these
remains. It will be noticed that the masonry was composed of river
bowlders not dressed or prepared in any way, and that the débris on the
ground would raise the walls scarcely to the height of a single low
story.
[Illustration: Plate XLII.
GATEWAY TO ANCIENT WORK, CLEAR CREEK.]
The location of these remains, their relation to other remains in the
vicinity, and their character all support the conclusion that they were
small temporary shelters or farming outlooks, occupied only during the
season when the fields about them were cultivated and during the
gathering of the harvest, as is the case with analogous structures used
in the farming operations among the pueblos of to-day. Their number and
distribution do not necessarily signify that all the terrace was under
cultivation at one time, although there is a fair presumption that the
larger part of it was, and the occurrence of the ditch at both the upper
and the lower ends of the area strengthens this conclusion.
As it is impossible that an area so large as this should be cultivated
by the inhabitants of one village, it is probable that a number of
villages combined in the use of this terrace for their horticultural
operations; and, reasoning from what we know to have been the case in
other regions, it is further probable that this combination resulted in
endless contention, and strife, and perhaps finally to the abandonment
of these fields if not of this region. The rectangular ruin already
illustrated is situated on a hill south of the terrace and overlooks it
from that direction; on the opposite side of Clear creek, on the hill
bounding the valley on the north, there are the remains of a large stone
village which commanded an outlook over the terraces in question; and a
little farther up the creek, on the same side and similarly situated,
there was another village which also overlooked them. There were
doubtless other villages and small settlements whose remains are not now
clearly distinguishable, and it is quite probable that some of the
inhabitants of the large villages in the vicinity, like those near
Verde, hardly 3 miles northward, had a few farming houses and some land
under cultivation on this terrace.
Thus it will be seen that there was no lack of cultivators for all the
tillable land on the terrace, and there is no reason to suppose that the
period when the land was under cultivation, and the period when the
villages overlooking it were occupied, were not identical, and that the
single-house remains scattered over the terrace were not built and
occupied at the same period. The relation of the stone villages to the
area formerly cultivated, the relation of the single-room remains to the
area immediately about them, the character of the remains, and the known
methods of horticulture followed by the Pueblo Indians, all support the
conclusion that these remains were not only contemporaneous but also
related to one another.