enlarged and G. K. Gilbert, with E. E. Howell, was appointed, each being attached to a party as geologist. In 1873, there was farther enlargement and a party was formed to map and to explore about half of the mountain region of Colorado, with as much of New Mexico as possible, an area of not far from 30,000 square miles, containing much extremely complicated geology. J. J. Stevenson was assigned to this party as geologist. The party consisted of Lieutenant (now Brigadier-General, retired) W. L. Marshall, two topographers, three “scientific workers,” an imposing array of packers and an escort of 25 infantry soldiers, who were to serve as protection against Indians. There were some good men in this escort, but before the season was well underway, there seemed to be reason for supposing that the authorities at Fort Leavenworth had unloaded their guardhouse on us. Ninety six mules of varying temperaments completed the equipment.
The request for a large appropriation from Congress had been enforced by proof that the work of previous years had been done at an almost incredibly small cost per square mile—and the argument was effective. The work in 1873 was to be an improvement on that of the past but the importance of economical operation was not to be forgotten. The geologist received a small mountain aneroid, a clinometer compass, a pocket level and a hammer; the naturalist-surgeon was equipped with a Spencer carbine of large bore, that he might shoot birds and other small animals; the collector in botany had his presses; the youthful barometer-carrier had his burden strapped on his back; the expedition was ready to start. After a series of misunderstandings with the mules, one of which led to a stampede which startled the youthful city of Denver, the party set forth in single file, as is the manner of mules.
The geologists associated with the Wheeler organization had gained some experience in the field, chiefly in connection with the Ohio survey, and they had gone with Wheeler in search of a wider field of usefulness. The field of the Colorado party proved very useful to me, but very soon I had misgivings as to my usefulness in that field. It became evident very quickly that geography, not geology, was the objective, and that the important elements in equipment of a geologist for this work were a lively scientific imagination and ability to solve stratigraphic puzzles by intuition. There was no map and the topographer’s notebook was of little service. The direction of travel was determined by conditions, so that, without a map, one could not keep his bearings in the maze of valleys and canons. The topographer was always secure, as the expedition was for him, but the geologist was in constant uncertainty. If he saw a section, which might relieve his perplexity, he was in anxious concern, knowing that if he measured the section, the train would disappear and he might be as a man hunting the needle in a haystack. But he had to secure sections, he had to examine anomalous exposures,