oved. We
also observed elders with flowers and leaves at the same time, and
the _Bambusa_ formed a thick light-green undergrowth in beautiful
contrast to the darker shades of the oaks, elders, and fan palms. The
latter were the last of their kind we saw on this side of the sierra.

We then went six miles further to the northeast. At first the trail
followed the little river, whose clear and rapid water is about a
foot deep and on an average six feet wide. Frequently its bed had
to be cleared of palm trees to make it passable for the pack train,
and big boulders and heavy undergrowth made travel rough. Then,
ascending a cordon which led directly up to the main range, we
followed for a while a dim trail on which the Apaches used to drive
the herds of cattle they had stolen, and which is said to lead to a
place so inaccessible that two Indians could keep a whole company at
bay. The surface soil we had lately been travelling over was covered
with boulders and fragments of conglomerate.

The Sierra Madre was now so close that the tilted masses of its rocks
seemed to overhang our tents threateningly where we had pitched them
at its foot. From this camp we had about the same splendid view as
from the ridge of Huehuerachi we had just left behind; and between
us and the foot-hills of the Sierra de Bacadehuachi stretched out a
vast mass of barren-looking rocks and hills. The Mexicans call them
_agua blanca_, a designation also applied to the small water course
that runs through them in a northerly and southerly direction, but
which from our point of view could not be made out in the chaotic
confusion. Away off toward the north, at a distance of from fifteen
to twenty miles, could be seen a high chain of sharp peaks.

I may mention here that I found the water of many streamlets and
brooks throughout the western mountains of Mexico to have a slightly
whitish colour and a dull, opalescent look, like a strong solution
of quinine. The Mexicans call it _agua blanca_, or _agua zarca_, and
consider it the best water they have. Many places, especially ranches,
are named after it. In the locality where we now found ourselves the
water had a slightly bitter taste, owing to a strong admixture of
iron and other minerals, but generally it was very palatable.

Here, only twenty-three miles from Nacori, and at an elevation
of 4,000 feet, we were obliged to make camp for three days. Dense
fogs and occasional hard showers made travel impossibl