Gaining the plains, the expedition took to the north-west, crossing several towns of prairie dogs, an animal nearly as large as a squirrel, which their head and teeth resembled; their bark was similar to that of a dog. One of their towns was about three miles long and one mile wide. Encamping on a stream with a little timber on its banks, which sheltered them from a cold drizzling rain, the next morning they discovered that during the night several horses had been stolen by Indians, who had cut the lariats by which some were tied within a few feet of where their owners were sleeping. Two days after, a party of three hunters met nine Indians; they understood Spanish, but would not give any satisfactory answers to questions put to them.

Again encountering high ridges of hills, through which, after severe toil, a passage brought them to a beautiful tableland covered with mesquit trees; as they advanced they came to a running stream of fresh water, where the notes of the robin, lark and blue-bird were heard, being the first they had met with on their journey. Resuming their march, which led over a broken country with a deep ravine, where the water was salt, a large party of Indians were seen driving off a drove of horses. Soon after, they discovered a stream of fresh water and an Indian camp just deserted.

A chain of rugged hills turned their course north. While stopping at a hole of muddy water, a party which had been in advance to find a road-way, returned and reported that to the north they had encountered several deep and impassable ravines. At the time, it was considered impossible to cross with the wagons the mountains on the west; and another party was sent out in a north-east direction. Lieutenant Hull, with four men, while in search of water a short distance from camp, were suddenly attacked by a large body of Indians; they were well armed, but before assistance could reach them, they were all killed and the bodies mutilated; two of their horses were also killed; the Indians being better mounted, fled on the approach of an opposing force. Afterwards, it was ascertained that twelve Indians were killed and several wounded.

Captain Strain, with a party, after two day's hard travel, returned and reported that there was a route by which the ravines might be headed in an easterly course but in no other direction. The command returned to a point higher up on the stream they had passed, where the commissary reporting only four days provisions on hand, a general consultation of all the officers was held, and it was resolved to dispatch a party of one hundred men to the settlements for a guide and provisions; while the rest remained at that place, which was called camp Resolution. Three men were missing, and never after heard from.

On the 31st of August, the advance party, under command of Colonel Wm. G. Cooke, with five days rations, being only about eight pounds of beef which they had dried since the preceding day, left their companions on one of the head branches of Red River. Taking a north-west course and striking a very plain Indian trail leading up the steppe or mountain side, which was only passable with horses. Reaching the summit, they found spread out before them a level plain. Soon after, they killed a bear. After twenty-four hours without water for their horses, they discovered a pond which refreshed them for their onward march.

Going forward at a rapid rate, they came suddenly on the brink of a chasm or canon that was some three hundred yards across and probably eight hundred feet in depth; after fruitless endeavors to find any way down the almost perpendicular banks, they encamped for the night on its edge, where they were visited by a tremendous thunder storm. Turning to the south, to head the torrent in the bed of the canon, they struck a large buffalo or Indian trail that led to the only place where there was any chance of crossing, which, after great difficulty, was accomplished. A few days after, they encountered another chasm of greater width and depth than the former one; fortunately it was near a trail. Their descent to its narrow bed was perilous, but made without accident. On reaching the bottom they found a small stream, and rested for a short time on a spot that within a few days past, had been occupied by a large body of Indians. On the fourth day out, with rations almost exhausted, they came upon a buffalo, which, on the second day's chase, was killed.

Persevering, the broad prairie was finally closing its bounds and ended by high, steep and rugged hills, which changed their course south-west until high conical and singularly formed hills turned them westward, when they reached the banks of a beautiful river, the Mora, where they found quantities of plums and grapes. Two of the men met Carlos and Brignoli; both said they had been lost and half starved from the time they had left them; they promised to go to camp, but never went. The next day, three mountains were seen resembling the Crows as described by Carlos. The scanty provisions of the men were consumed, and hunger compelled them to kill a horse for food.

On the thirteenth day of their wanderings they fortunately discovered a cart road, and soon after a few Mexicans at the Narrows, a ledge of rocks on the banks of the Angosturos. The Mexicans said that by going directly west from where they had started, on the Palo Duro, a good mule could travel the distance in four days, and over a good smooth road; and that San Miguel was about eighty miles distant. Three of the Mexicans were employed to go with a Mexican servant of the party, to the command, with letters. They made the trip in less than four days.