alls, and dams, erected by
an extinct race once possessing these regions." Mr. A. F. Bandelier,
on his journey to the Upper Yaqui River, in 1885, which took him as
far as Nacori, also refers to them, and Professor W. J. McGee, on his
expedition in 1895, found in Northeastern Sonora ruins locally known as
_Las Trincheras_, which he considered the most elaborate prehistoric
work known to exist in Northwestern Mexico. They comprise, he says,
terraces, stone-walls, and inclosed fortifications, built of loose
stones and nearly surrounding two buttes.

I must not omit to mention that in a week's exploration in the
mountains near Nacori, Mr. Stephen and his party did not find any
pottery fragments, nor flint flakes, nor grinding stones. They reported
that there was in that region no other trace of an early people than
the hundreds of trincheras in the lower portions of the arroyos.

Noteworthy, however, was the frequent occurrence of old trails across
the hills, some quite plainly traceable for three and four hundred
yards. Old oaks stretched their limbs across many of them quite close
to the ground.

While at Nacori I learned from the inhabitants that at no great
distance from their town there were several deposits containing _huesos
giganteos_ (giants' bones), a name given to fossils in this part of the
world, where the people imagine that the large bones were originally
those of giants. I had then neither time nor men to make excavations
of any importance; but Mr. White, the mineralogist of the expedition,
whom I sent to look into the matter, and who devoted a week to the
examination of the deposits, reported that one of them, in a valley
sixteen miles south of Nacori, was a bed of clay thirty feet thick and
about a mile and a half long. On the edge of this field he discovered
a tusk six feet eight inches long and twenty-six inches at its widest
circumference, and having almost the curve of a circle. It was not
petrified and had no bone core, but the hole filled in with clay,
and its colour was a rich mahogany. It was undoubtedly the tusk of
a mammoth.

From the beginning it had surprised me how very ignorant the people
of Sonora were regarding the Sierra Madre. The most prominent man
in Opoto, a town hardly forty miles from the sierra, told me that
he did not know how far it was to the sierra, nor was he able to say
exactly where it was. Not even at Nacori, so close to this tremendous
mountain range, was there much i