172 GUIDEBOOK OF THE WESTERN UNITED STATES. 
the point of greatest height the walls decrease gradually and finally 
disappear near the mouth of Elk Creek, a small stream that joins 
Gunnison River from the north. The granite, however, does not 
completely disappear but extends down to milepost 306, or 1 mile 
above Cebolla (say-bo’yah), where it passes below water level. 
Cebolla, which is one of the most noted resorts on the river for 
fishermen, is in a wide part of the valley on the north side of the 
river, at a mesa known as Tenderfoot Hill. The top 
cohalls, ¢ of this mesa is 1,200 feet above the track at 
inde iii ty Cebolla. The granite does not remain below river 
level any great distance, for within a mile of Cebolla 
it forms the walls of a narrow canyon, which, however, are not 
more than 100 feet high. The smoothness and regularity of the 
upper surface of the granite and the way in which it rises and 
falls with reference to river level make it comparatively easy for 
the traveler to understand how the Black Canyon has been cut. It 
is evident that at the time the river established its course the granite 
in neither of the small canyons so far described nor in Black Can- 
yon was exposed, for the river was then flowing on the softer sedi- 
mentary rocks that overlay the granite. As the river cut deeper 
into its bed it uncovered the granite, but it could not shift its course 
and thereby avoid the hard rock, so it had to keep at work laboriously 
cutting its way into the granite. Although the granite canyons 
about Cebolla are now shallow, they will become deeper and deeper 
in course of time until the entire route from Gunnison to Cimarron 
may be one granite canyon as deep and as impressive as the “ Black 
Canyon.” It may be well to say that this great canyon will not be 
seen by the coming generation nor the generation after the next, 
nor even the one following that; but the geologist knows that unless 
conditions change such a canyon will be formed, although the time 
may be thousands or millions of years hence. 
Below Cebolla the canyon is much the same as it is above that 
place, except that the slopes above the granite become greater and 
in places are composed of vast masses of volcanic breccia that 
weather into fantastic forms. Where the granite is above the level 
of the river the canyon is more or less rugged, but where it is below 
the surface the valley is wide and the slopes are smooth and gentle. 
Near milepost 313 the granite passes below the level of the river 
-and remains concealed as far as the village of Sapinero (sah-pe- 
nay’ro), which is a noted fishing resort and the 
Sapinero. = junction of the branch railroad that runs south- 
Denver $14 miles, | Sapinero the traveler, by looking back, may obtain 
an excellent view of a great cliff of voleanic breccia 
see Pl, LX-X, A), and by looking forward he may see the granite 
