One of the characteristic features of the Mimbres ruins, but not
peculiar to them, are mortars or circular depressions worn in the
horizontal surface of rock in place. They are commonly supposed to
have been used as mortars for pounding corn, and vary in size from two
inches to a foot in diameter, being generally a foot deep. We find
them occurring alone or in clusters. Good examples of such depressions
are found near the Byron ruin, in the neighborhood of the ruins along
Whiskey Creek, at Oldtown, and elsewhere. There is a fine cluster of
these mortars nine miles from Deming, near the pictographs in the
Cook’s Range. Similar mortars have been repeatedly described and often
figured. Mr. Webster has given the most complete account of this type
of mortars in a description of the ancient ruins near Cook’s Peak.[22]
On the surface of the southwestern point of a low hill to the north of
an ancient ruin at Cook’s Peak, according to this observer,
occurs a feature which the writer had nowhere else seen, save on
the east side of the same mountain. I refer to the great number
of mortars which occur in this sandstone back a few feet to the
north of the ruins, and which were made and long used by the
ancient pueblo-dwellers. There exists at this one place fifty-three
of these mortars, nearly all of them occurring in an area of
surface not more than seventy-five or eighty feet in diameter....
Nearly all the mortars are circular or sub-circular in outline,
symmetrical and smooth inside, and the upper edge or margin usually
rounded by the pestle. In a few cases, however, these mortars have
an oblong or subovate outline, somewhat like some forms of metates
found among the ruins.
These mortars often contract to a point at the bottom, when
circular in marginal outline, although at times are longer than
broad, as just stated, and in this case have a more flattened
bottom. They vary from two to eleven inches in diameter, the
smallest forms being those apparently only just begun, and are few
in number. The deepest mortar observed was seventeen inches, though
the great majority of them would vary perhaps from four to ten
inches in depth. Often the rock was smooth and polished around the
margin of the mortars, and [their distances apart] vary from a few
inches to several feet from each other.
At times these mortars would be located on the top of a large block
of sandstone which might happen to occupy this area; these boulders
sometimes being four to five feet in diameter and perhaps four feet
in height. It was plain to be seen that this ancient mill-site was
long used by these peculiar people, but just why so many quite
similar mortars should have been made here and used by these people
is a matter of conjecture.
It seems certain that a sufficiently large number of people could
not have been congregated here, under ordinary conditions, to
warrant the forming of so many mortars for the purpose of grinding
food.[23]
The present writer accepts the theory that these rock depressions
were used in pounding corn or other seeds, but their great number in
localities where ruins are insignificant or wanting is suggestive.
We constantly find arable land near them, indicating that communal
grinding may have been practised, and suggesting a large population
living in their immediate neighborhood, which may have left no other
sign of their presence.