Rock Hills (the highest point north of Mount Bryan,) gradually decreasing
in elevation, and, if possible, increasing in barrenness. The summits of
those hills I found invariably rock--generally sandstone--the lower
slopes covered with dense brush, and the valleys with low scrub, with
occasional small patches of thin wiry grass. I was obliged to return on
the third day, and reached the foot of Mount Bryan on the fourth evening,
at the southern extremity of which hill the horses were nearly bogged in
the soft ground, though only fifty miles distant from land where the dust
was flying as if in the midst of summer.

"It appears to me certain, from the result of these different attempts,
that there is no country eastward of the high land extending north from
Mount Bryan, as far as Mount Hopeless, a distance of about three hundred
miles, as far as the meridian of 141 degrees (and probably much beyond
it), available for either agricultural or pastoral purposes; and that,
though there may be occasional spots of good land at the base of the main
range on the sources of the numerous creeks flowing from thence towards
the inland desert, these must be too limited in extent to be of any
present value.

"The nature of the formation of the main range I found generally
iron-stone, conglomerate and quartz, with sandstone and slate at the
lower elevation. At the points of highest elevation from Mount Bryan
northward, igneous rocks of basaltic character protruded from below,
forming rugged and fantastic outlines.

"At one spot, particularly, about 30 degrees, there were marked
indications of volcanic action, and several hollows resembling small
craters of extinct volcanoes, near one of which we found a small spring
of water, maintaining always a temperature of about 76 degrees Farenheit,