We were now in the narrowest part of the upper portion of the Grand Canyon, the distance from rim to rim at one point being close to six miles.  The width at Bright Angel varied from eight to fourteen miles.  The peaks rising from the plateau, often as high as the canyon walls, and with flat tops a mile or more in width, made the canyon even narrower, so that at times we were in canyons close to a mile in depth, and little over four miles across at the tops.

In this section of the granite there were few places where one could climb out.  Nearly all the lateral canyons ended quite a distance above the river, then fell sheer; the lower parts of the walls were quite often smooth-surfaced, where they were polished by the sands in the stream.  The black granite in such cases resembled huge deposits of anthracite coal.  Sections of the granite often projected out of the water as islands, with the softer rock washed away, the granite being curiously carved by whirling rocks and the emery-like sands.  Holes three and four feet deep were worn by small whirling rocks, and grooves were worn at one place by growing willows working back and forth in the water, the sand, strange to say, having less effect on the limbs than it had on the hard rocks.

About noon of the day following this upset we reached the end of the Bass Trail and another cable crossing, about sixty feet above the water.  Three men were waiting for us, and gave a call when we rowed in sight of their camp.  One was Lauzon’s brother, another was Cecil Dodd, a cowboy who looked after Bass’ stock, and the breaking of his horses, the third was John Norberg, an “old timer” and an old friend as well, engaged at that time in working some asbestos and copper claims.

The granite was broken down at this point, and another small deposit of algonkian was found here.  There were intrusions, faults, and displacements both in these formations and in the layers above.  These fractures exposed mineral seams and deposits of copper and asbestos on both sides of the river, some of which Bass had opened up and located, waiting for the day when there would be better transportation facilities than his burros afforded.

This was not our first visit to this section.  On other occasions we had descended by the Mystic Spring (or Bass) Trail, on the south side, crossed on the tramway and were taken by Bass over some of his many trails, on the north side.  We had visited the asbestos claims, where the edge of a blanket formation of the rock known as serpentine, containing the asbestos, lay exposed to view, twisting around the head of narrow canyons, and under beetling cliffs.  We went halfway up the north rim trail, through Shinumo and White canyons, our objective point on these trips being a narrow box canyon which contained a large boulder, rolled from the walls above, and wedged in the flume-like gorge far above our heads.  This trail continues up to the top, going over the narrow neck which connects Powell’s Plateau—­a segregated section of thickly wooded surface several miles in extent—­with the main extent of the Kaibab Plateau.