the
greatest declivity occurs in the Uinta region, in the Canyon of Lodore.
The profile of the river in these two districts is approximately given
on page 57. The average depth of the Grand Canyon is about 4000 feet.
Its width at the top varies from 4 1/2 to 12 miles. This is the extreme
outer cliff-line. The inner gorge is much narrower, at the Toroweap
being only about 3500 feet. The river varies in width from 500 or 600
feet to 75 or 100. In this canyon is water-power enough to run the
machinery of the world, and there is as much more in the canyons above.

Joining Marble Canyon on the north is Glen, 149 miles long, from the
Paria to Fremont River. It has but one rapid of consequence. At high
water, with the exception of this rapid, the tide sweeps smoothly and
swiftly down with a majestic flow. The walls are homogeneous sandstone,
in places absolutely perpendicular for about a thousand feet. I have
stood on the brink and dropped a stone into the river. The highest walls
are 1600 feet. Next is Narrow Canyon, about 9 miles long, 1300 feet
deep, and no rapids. It is hardly more than the finish of Cataract, a
superb gorge about 40 miles long with a depth of 2700 feet, often nearly
vertical. The rapids here are many and violent, the total fall being
about 450 feet. At its head is the mouth of the Grand River. The
altitude of the junction is 3860 feet.* Following up the Green, we have
first Stillwater, then Labyrinth Canyon, much alike, the first 42 3/4
and the second 62 1/2 miles in length. The walls of sandstone are 1300
feet. Their names well describe them, though the stillwater of the first
is very swift and straight. There are no rapids in either. All these
canyon names, from Green River Valley to the Grand Wash, were applied by
Powell. Between Labyrinth and the next canyon, Gray, so called from the
colour of its walls, 2000 feet high, is Gunnison Valley, where the river
may first be easily crossed. Here the unfortunate Captain Gunnison, in
1853, passed over on his way to his doom, and here, too, the Old Spanish
Trail led the traveller in former days toward Los Angeles. The Denver
and Rio Grande Western Railway has taken advantage of the same place to
cross. The 36 miles of Gray are hardly more than a continuation of the
Canyon of Desolation's 97 miles. Desolation is a fine chasm, whose walls
are 2400 feet. The view on page 206 gives an excellent idea of their
average character. The mouth of the Uinta River, not far a