The salt of this lake is superior to any other found in the southwest, not excepting that of the Manzano salinas, east of the Rio Grande, which nevertheless was as strenuously fought for and guarded by the Tanoan tribes settled around these salinas, and had in like manner, indeed, drawn their ancestry down from earlier cavate homes in the northern mountains. Hence it was preferred (as it still is by both Indian and white population of New Mexico and Arizona) to all other kinds, and commanded such price that in the earlier cliff-packs I have found it adulterated with other kinds from the nearer salt marshes which occur in southern Utah and southwestern Colorado. That the adulteration of the lake salt with the slightly alkaline and bitter salt of the neighboring marshes was thus practiced with a view to eking out the trade supply is conclusively shown, I think, by the presence in the same cliff homes from which the adulterated specimens were obtained, of abundant specimens of the unadulterated salt, and this as conclusively shows not only that the cliff dwellers traded in this salt, as do their modern Zuñi representatives, but also that it was then, as now, more highly valued than other kinds of salt in the southwest. The influence on the movements of whole tribes of people which it is here assumed such a source of favorite salt supply as this exerted over the early cliff dwellers, does not stand alone in the history of American tribes. It already has been intimated that the Tanoans so far prized their comparatively inferior source of salt supply in the salinas of the Manzano as to have been induced to settle there and surround them with a veritable cordon of their pueblos. Another and far more significant instance, that of the Cerro de Sal in Peru may be mentioned, for in that country not only was salt of various kinds to be found in many valleys and throughout nearly all the deserts of the Medano region extending from northern Ecuador to southern Chili, but the sea also lay near at hand along the entire western border of this vast stretch of country; yet from remote parts of South America trails lead, some from the Amazon and from Argentina, more than a thousand miles away, some from nearer points and from all local directions to this famous "Cerro de Sal." The salt from this locality was, like that of the Lake of Salt, so highly prized that it drew aboriginal populations about it in even pre-Incan days, and was a source of supply, as well as, it is affirmed, of abundant tribute to those dominant Pueblos of South America, the Incas of later days.[4] [4] A parallel world example of the influence of salt sources on the movements of primitive peoples may be found in the fact that all the great historic trade routes across Asia were first established along salt trails of prehistoric times.