OBITUARY NOTICES. 
477 
ant Warren, engaged in explorations in Nebraska and Da¬ 
kota. From 1859 until 1862 he was surgeon, naturalist, and 
geologist with Capt. W. F. Raynolds, in the exploration of 
the Yellowstone and Missouri rivers. In October, 1862, he 
was appointed acting assistant surgeon of volunteers, and 
was connected with the army as assistant surgeon and 
assistant medical inspector until June, 1865, when he re¬ 
signed, and was brevetted lieutenant colonel for meritorious 
services during the war. He then resumed his scientific 
work, and in 1866 made another trip to the Bad Lands of 
Dakota, this time in the interest of the Academy of Natural 
Sciences of Philadelphia. In 1865 he was elected professor 
of mineralogy and geology in the University of Pennsylva¬ 
nia, which position he resigned in 1872. From 1867 to 
1879 his history is that of the organization of which he had 
charge, which began as a geological survey of Nebraska 
and became finally the Geological Survey of the Territo¬ 
ries. In the winter of 1871-72 he succeeded in having the 
Yellowstone National Park made a Government reserva¬ 
tion, the bill setting it apart having been chiefly written 
by himself. From 1879 until December, 1886, he was 
connected with the United States Geological Survey as 
geologist. His health began to fail soon after his connec¬ 
tion with this organization, and gradually became worse, 
and he lived only a year after his resignation. 
In 1876 the degree of LL. D. was conferred upon him by 
the University of Rochester, and in June, 1886, he received 
the same degree from the University of Pennsylvania. He 
was a member of seventeen scientific societies in the United 
States, among them the National Academy of Sciences, and 
was honorary and corresponding member of some seventy 
foreign societies.' A bibliography of his writings includes 
158 titles. 
Dr. Hayden was one of the pioneers in the geological in¬ 
vestigations of the West, among whom,® as the Director of 
the Geological Survey of Great Britain has said, his name 
will always hold a high and honored place. He made the 
