During Mallery's tenure with the Signal Corps, he was briefly stationed at
Fort Rice in
Dakota Territory, where the indigenous system of communication by signs and gestures attracted his attention. He began to make note of them, which led to a parallel investigation of the pictographs on rocks, skins, and bark, of which he made a large number of transcriptions. He foresaw that these customs would ultimately be lost and forgotten as the Indians were brought more and more under the control of the authorities. Before Mallery began his researches, European Americans generally supposed that the pictographs, some of which were believed to be of
pre-Columbian origin, were simply pictures and devoid of meaning. He was gradually convinced that gesture-speech and the cognate pictographs formed a complete system, involving mythology and history and having an important relation to the spoken language. In 1877, as a result of this work, he was ordered to report to Major
John Wesley Powell, who was doing a survey of the
Rocky Mountain region. Later, when Mallery retired from the Army, Powell arranged for his appointment as an ethnologist with the
Bureau of American Ethnology, which had been established that year. In 1880 Mallery produced a 72-page pamphlet, with 33 figures, entitled "Introduction to the Study of Sign-language among the North American Indians as Illustrating the Gesture-speech of Mankind". This was intended as a manual for students. In the same year, he prepared a
quarto volume of 329 pages, entitled "A Collection of Gesture Signs and Signals of the North American Indians, with Some Comparisons." The latter work was distributed to collaborators only. In 1881 Mallery's second important contribution was published in the First Annual Report of the Bureau, namely, "Sign-language among North American Indians Compared with that Among other People and Deaf-mutes." This treatise comprised 290 pages and was illustrated with 13 plates, a map, and 285 figures. While intended by its author as a preliminary report only, it is now considered to be the first authoritative exposition upon an almost entirely new subject in the field of
anthropology. Mallery's next publication appeared in the Fourth Annual Report of the Bureau, under the title, "Pictographs of the North American Indians; a Preliminary Paper." It consisted of 256 pages, illustrated with 83 plates and 209 figures. Finally, the Tenth Annual Report of the Bureau was devoted to Mallery's completed work on one of his subjects of investigation. It was entitled, "Picture-writing of the American Indians," filling 807 quarto pages, with 54 plates and 1,290 figures. Mallery's work included a recognition of winter counts of various tribes, which were documented in pictures and visual means, were important keys to their histories, together with oral history transmission. At the time of his death, Mallery was preparing a treatise on the sign-language of the American Indians, intended to be a companion work to "Picture-writing". This was left unfinished and had to be completed by his colleagues at the Bureau. In 1882, Mallery was elected as a member of the
American Philosophical Society. ==Other activities==