at some convenient point in the State of Sonora, Mexico, that great
and mysterious mountain range called the Sierra Madre, cross it to
the famous ruins of Casas Grandes in the State of Chihuahua, and then
to explore the range southward as extensively as my means would permit.

The western Sierra Madre may be considered a continuation of the
Rocky Mountains and stretches through the greater part of Mexico into
Central and South America as a link of the Cordilleras, which form a
practically uninterrupted chain from Bering Strait to Cape Horn. The
section occupying Northwestern Mexico is called Sierra Madre del
Norte, and offers a wide field for scientific exploration. To this
day it has never been surveyed.

The northernmost portion of the Sierra Madre del Norte has from time
immemorial been under the dominion of the wild Apache tribes whose hand
was against every man, and every man against them. Not until General
Crook, in 1883, reduced these dangerous nomads to submission did
it become possible to make scientific investigations there; indeed,
small bands of the "Men of the Woods" were still left, and my party
had to be strong enough to cope with any difficulty from them.

Inasmuch as my expedition was the first to take advantage of the
comparative security prevailing in that district, I thought that
I could best further the aims of Science by associating with me a
staff of scientists and students. Professor W. Libbey, of Princeton,
N. J., took part as the physical geographer, bringing with him his
laboratory man; Mr. A. M. Stephen was the archaeologist, assisted
by Mr. R. Abbott; Messrs. C. V. Hartman and C. E. Lloyd were the
botanists, Mr. F. Robinette the zooelogical collector, and Mr. H. White
the mineralogist of the expedition.

All the scientific men were provided with riding animals, while the
Mexican muleteers generally rode their own mounts. Our outfit was
as complete as it well could be, comprising all the instruments
and tools that might be required, besides tents and an adequate
allotment of provisions, etc. All this baggage had to be transported
on mule-back. We were, all in all, thirty men, counting the scientific
corps, the guides, the cooks, and the muleteers, and we had with us
nearly a hundred animals--mules, donkeys, and horses--as we crossed
the sierra.

It was a winter campaign, and from Nacori, in Sonora, to Casas
Grandes, in Chihuahua, we were to make our own trail, which we did
successfull