settlement. The various springs laid down by Gray, Emory, Parke,
and Bartlett, will all afford water for small settlements, and
their supply can be much increased by a judicious outlay of
money. The Rio Grande valley is very rich, and in places of great
width. The Mesilla valley already contains a population of about
five thousand souls, and there is ample room for many more.

If, as proposed, the Northern boundary of the Arizona Territory
should enclose the Northern branches of the Gila, an agricultural
region will be opened to settlement sufficient in itself to
sustain the population of an immense agricultural State. Col.
Bonneville, who is now at the head of a large force exploring
this region, writes to the Secretary of War that it is the finest
country he has ever seen, "valleys capable of sustaining a
population of twenty thousand each, teeming at every step with
evidences of an immense population long ago-and an ancient and
superior civilization." The Hon. John R. Bartlett says of the
"Salinas," one of the Northern branches of the Gila, that it
alone will supply food for a great State. It must be recollected,
in this connection, that the great mineral wealth of Arizona will
call for and amply repay for the redemption and expensive
cultivation of all the available lands, and that irrigation
produces immensely greater crops than the other method of
planting. Throughout the whole of Utah, irrigation has been
resorted to with the greatest success. The soil in Utah, in no
place that the writer saw it, could in any way be compared to
that of the bottom lands of Arizona.

Captain Whipple in his valuable report of exploration for the
Pacific Railroad, published by order of Congress, crossed the