In depth it could not have been less than one thousand feet, in width from three to five hundred yards, and at the point where we first struck it, its sides were nearly perpendicular.  A sickly sensation of dizziness was felt by all three of us, as we looked down, as it were, into the very bowels of the earth.  Below, an occasional spot of green relieved the eye, and a stream of water, now visible, now concealed behind some huge rock, was bubbling and foaming along.  Immense walls, columns, and, in some places, what appeared to be arches, filled the ravine, worn by the water undoubtedly, but so perfect in form, that we could with difficulty be brought to believe that the hand of men or genii had not been employed in raising them.  The rains of centuries, failing upon the extended prairie, had here found a reservoir and vent, and their sapping and undermining of the different veins of earth and stone had formed these strange and fanciful shapes.

Before reaching the chasm, we had crossed numerous large trails leading a little more to the westward than we had been travelling, and we were at once convinced that they all centred in a common crossing close at hand.  In this conjecture we were not disappointed; half-an-hour’s trotting brought us into a large road, the thoroughfare for years of millions of Indians, buffaloes, and mustangs.  Perilous as the descent appeared, we well knew there was no other near.  My horse was again started ahead while the two others followed.  Once in the narrow path, which led circuitously down the deep descent, there was no possibility of turning back, and our maddened animals finally reached the bottom in safety.

Several large stones were loosened from under our feet during this frightful descent.  They would leap, dash, and thunder down the precipitous sides, and strike against the bottom far below us with a terrific crash.

We found a running stream at the bottom, and on the opposite side of it a romantic dell covered with short grass and a few scattered cotton-wood trees.  A large body of Indians had encamped on this very spot but a few days previous; the blazed limbs of the trees and other “signs” showing that they had made it a resting-place.  We, too, halted a couple of hours to give our horses an opportunity to graze and rest themselves, The trail which led up to the prairie on the opposite side was discovered a short distance above us to the south.

As we journeyed along this chasm, we were struck with admiration at the strange and fanciful figures made by the washing of the waters during the rainy season.  In some places, perfect walls, formed of a reddish clay, were to be seen standing; in any other locality it would have been impossible to believe but that they had been raised by the hand of man.  The strata of which these walls were composed was regular in width, hard, and running perpendicularly; and where the softer sand which had surrounded them had been washed away, the strata still remained, standing in some places one hundred feet high, and three or four hundred in length.