In 1877, under orders from General Philip Sheridan (later in 1883, Commanding General of the United States Army), Lt. William Lewis Carpenter made his final report on the Geology and Natural History of the Big Horn Mountains. This report provided the economic reasons of the land and gold rush into the Black Hills of South Dakota 1873-1877, and was well received by the scientific community. Nominated by geologist W. P. Jenney, who encouraged him to go into academics, William L. Carpenter was elected a Fellow of the American Association for the Advancement of Science on September 4, 1877.