The yellow bed of the Niobrara group disappears to the south-west, west, and north-west of Fort Wallace, beneath a sandy conglomerate of uncertain age. Its color is light, sometimes white, and the component pebbles are small and mostly of white quartz. The rock wears irregularly into holes and fissures, and the soil covering it generally thin and poor. It is readily detached in large masses, which roll down the bluffs. No traces of life were observed in it, but it is probably the eastern margin of the southern extension of the White River Miocene Tertiary stratum. This is at least indicated by Dr. Hayden, in his geological preface to Leidy's extinct mammals of Dakota and Nebraska. Commercially, the beds of the Niobrara formation possess little value, except when burned for manure. The yellow chalk is too soft in many places for buildings of large size, but will answer well for those of moderate size. It is rather harder at Fort Hays, as I had occasion to observe at their quarry. That quarried at Fort Wallace does not appear to harden by exposure; the walls of the hospital, noted by Leconte on his visit, remained in 1871 as soft as they were in 1867. A few worthless beds of bituminous shale were observed in Eastern Colorado. The only traces of Glacial Action in the line explored were seen near Topeka. South of the town are several large, erratic masses of pink and bloody quartz, whose surfaces are so polished as to appear as though vitrified. They were transported, perhaps, from the Azoic area near Lake Superior. CHAPTER XXV. A SAVAGE OUTBREAK--THE BATTLE OF THE FORTY SCOUTS--THE SURPRISE--PACK-MULES STAMPEDED--DEATH ON THE ARICKEREE--THE MEDICINE MAN--A DISMAL NIGHT--MESSENGERS SENT TO WALLACE--MORNING ATTACK--WHOSE FUNERAL?--RELIEF AT LAST--THE OLD SCOUTS' DEVOTION TO THE BLUE. On our return to Sheridan we were deeply pained to hear of the sad death of Doctor Moore and Lieutenant Beecher, whose acquaintance we had formed at Fort Hays, and the former of whom we had learned to esteem most highly as a personal friend. A scouting party, not long before, had left the post just named, under the command of General Forsythe, of Sheridan's staff, and composed principally of those citizens who had seen frontier service. Dr. Moore accompanied it as surgeon, and Lieut. Beecher--a nephew of Henry Ward Beecher, and an officer of the regular army--held the position of chief of scouts, which he had filled for some time previously with much credit. The savages of the plains being again upon the war-path, that brave and well-organized little party of fifty were dispatched to pursue a band of Indians, which had appeared before Sheridan and run off a lot of stock.