"He studied medicine with Dr. J. S. Newberry, at Cleveland, and at Albany was graduated Doctor of Medicine in the early part of 1853. After his graduation, he was sent by Prof. James Hall, of New York, to the Bad Lands of White River, in Dakota. The years 1854 and 1855 he spent exploring and collecting fossils in the Upper Missouri country, mainly at his own expense. From 1856 until 1859, he was connected as geologist with the expeditious of Lieutenant Warren, engaged in explorations in Nebraska and Dakota. From 1859 until 1862, he was surgeon, naturalist, and geologist with Captain W. F. Raynolds, in the exploration of the Yellowstone and Missouri Rivers. In October, 1862, he was appointed acting assistant surgeon and assistant medical inspector until June, 1865, when he resigned, 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 Pennsylvania, 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 Territories.... From 1879 until December, 1886, he was connected with the United States Geological Survey as geologist. His health began to fail soon after his connection 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. "... The gentleness and diffidence, approaching even timidity, which impressed his fellow-students at Oberlin, characterized Dr. Hayden throughout his life, and rendered it somewhat difficult for those who did not know him intimately to understand the reasons for his success, which was undoubtedly due to his energy and perseverance, qualities which were equally characteristic of him as a boy and student and in later life. His desire to forward the cause of science was sincere and enthusiastic, and he was always ready to modify his views upon the presentation of evidence. He was intensely nervous, frequently impulsive, but ever generous, and his honesty and integrity undoubted. The greater part of his work for the government and for science was a labor of love." _Jones Pass_ (9,450)--K: 12--1880--Norris--For its discoverer, Captain W. A. Jones, Corps of Engineers, U. S. A., who passed through it in 1873.