If by the word Aztlan was intended "place of Cranes", and on the supposition that these tribes migrated from the San Juan region, the reasons for the designation are justified. The Sandhill Crane (Grus Canadensis) is one of the largest and most conspicuous of American birds, and is still found from the British Possessions to New Mexico, and winters in the latter. I saw a pair of these great birds in 1878, in the valley of the Animas River. Dr. Cones remarks that "thousands of Sandhill Cranes repair each year to the Colorado River Valley, flock succeeding flock along the course of the great stream from their arrival in September until their departure the following spring. Taller than the Wood Ibises or the largest Herons with which they are associated, the stately birds stand in the foreground of the scenery of the valley…. Such ponderous bodies moving with slowly-beating wings give a great idea of momentum from mere weight, a force of motion without swiftness; for they plod along heavily, seeming to need every inch of their ample wings to sustain themselves." [Footnote: Birds of the Northwest, 1874, p. 534.]
It is an Indian trait to mark localities by some conspicuous feature or fact, and the selection of the Sandhill Crane to indicate their home country would have accorded with Indian usages.
Again, Herrera, who presents the current traditions, observes, that "these peoples painted their original in the manner of a cave, and said they came out of seven caves to people the country of Mexico…. After the six above mentioned races departed from their country, and settled in New Spain, where they were much increased, the seventh race being the Mexican nation, a warlike and polite people, who adoring their god Vitsilpuztli, he commanded them to leave their own country, promising them they should rule over other races in a plentiful country, and much wealth." [Footnote: History of America, iii, p. 188, 190.]
It is worthy of remark that the cave dwellings or cliff houses are in the San Juan district, the most of them being on the Mancos River, and on the western portion of the San Juan. These traditions may in fact refer to these cave dwellings as the original homes of their ancestors, and at the same time without precluding the supposition that they also constructed and inhabited some of the pueblo structures now in ruins in other parts of the same area. All the early accounts concur in representing the Aztecs or Mexicans, when they first arrived in Mexico, as subsisting by the cultivation of maize and plants, as constructing houses of stone, and with a religious system which recognized personal gods. These statements are probably true. They had attained to the statue of Village Indians. This again renders New Mexico their probable original home as the only area in the north where ruins of structures of tribes so far advanced have been found.
The San Juan district is remarkably situated in its geographical relations. This river, rising in the crests of the high mountains forming the water-shed or divide between the Atlantic and Pacific, flows southward until it enters the table-land formation, through which it flows in a southwesterly and then northwesterly direction, making a long, sweeping curve in New Mexico and Arizona, after which it runs westerly to its confluence with the Colorado. It receives from the north the following tributaries, rising like itself in the high mountains, the Piedra, Pine River (Los Pinos), the Animas, the La Plata, the Mancos, the McElmo, now dry, and the Hovenweep and Montezuma creeks, now nearly dry. Its southern tributaries are the Navajo, Chaco, and De Chelly.
With such evidences of ancient occupation, here and elsewhere in the San Juan country, we are led to the conclusion that the Village Indians increased and multiplied in this area, and that at some early period there was here a remarkable display of this form of Indian life, and of house architecture in the nature of fortresses, which must have made itself felt in distant parts of the continent. On the hypothesis that the valley of the Columbia was the seed-land of the Ganowanian family, where they depended chiefly upon a fish subsistence, we have in the San Juan country a second center and initial point of migrations founded upon farinaceous subsistence. That the struggle of the Village Indians to resist the ever continuous streams of migration flowing southward along the mountain chains has been a hard one through many centuries of time, is proved by the many ruins of abandoned or conquered pueblos which still mark their settlements in so many places. At the present moment there is not a Village Indian in the San Juan district. It is entirely deserted of this class of inhabitants.
That the original ancestors of the principal historic tribes of Mexico once inhabited the San Juan country is extremely probable. That the ancestors of the principal tribes of Yucatan and Central America owe their remote origin to the same region is equally probable. And that the Mound Builders came originally from the same country, is, with our present knowledge, at least a reasonable conclusion.
Indian migrations have occurred under the influence, almost exclusively, of physical causes, operating in a uniform manner. These migrations, involving the entire period of the existence here of the inhabitants of both American continents, will be found to have a common and connected history. A study of all the facts may yet lead to an elucidation and explanation of these migrations with some degree of certainty. The hypothesis that the valley of the Columbia River was the seed-land of the Ganowanian family holds the best chance of solving the great problem of the origin and distribution of the Indian tribes.
[Relocated Footnote: Where maize was indigenous is unknown, except that it was somewhere upon the American continent. It is the only cereal America has given to the world. At the period of European discovery, it was found cultivated and a staple article of food in a large part of North America and in parts of South America. There were also found beans, squashes, and tobacco, with the addition in some areas of peppers, tomatoes, cocoa and cotton. The problem of the place of the origin of maize is probably insoluble, but speculations are legitimate and such are all I have to offer.
The fecundity of plant-life in the Rocky Mountains is remarkable, particularly on the southern slopes, where they subside into the mesa, or table-land formation, north of the San Juan River. The continental divide is in the eastern margin of the region. The first suggestion I wish to make is that all cereals and cultivated plants must have originated in the great continental mountains of the two hemispheres, and have propagated themselves along the water courses of the mountain valleys down to the plains traversed by the great rivers formed by these mountain tributaries. All the cereals belong to the family of the Grasses (Gramineae), and each of them, doubtless, is the last of a series of antecedent forms.