On the upper Gila River in Arizona, Fewkes discovered traces of reservoirs and irrigating canals. “The large circular or elongated oval depressions,” he says, “in the immediate neighbourhood of some of the house-mounds have been identified as the sites of former reservoirs.... The reservoir at Buena Vista is one of the largest that was discovered, yet no irrigating ditches leading into it were distinctly traced.... There is abundant evidence that the ancient people of the Pueblo Viejo Valley led the water from the Gila River over the plain by means of canals for purposes of agriculture, for in many places the depressions marking the old ditches may be traced for considerable distances.... I have been informed by some of the older residents that when they came into the country, before the Montezuma and San José irrigation ditches had been constructed, the ancient aqueducts were much more conspicuous than they are to-day, and that sections of the modern ditches follow the course of the ancient waterways.”[301] [Illustration: A VOTIVE ADZ OF JADITE FROM MEXICO, SHOWING FRONT AND SIDE Height, 10¹³⁄₁₆ in.; width, 6 in.; thickness, 4⅝ in. Highly polished; color light grayish green with streaks of emerald green on the back. A complete human figure. See page 341 for back. From _Monumental Records_ American Museum, Kunz Collection ] The Aztecs built long aqueducts to supply their towns, and the Mayas constructed large reservoirs. Charnay says: “According to historians of the Conquest, El Salto del Agua (a monumental fountain in the City of Mexico) and the aqueduct which it terminates replaced the ancient aqueduct of Montezuma constructed by Netzahualcoyotl, King of Tezcuco, between the years 1427 and 1440. At that time it was brought through an earthen pipe to the city, along a dyke constructed for the purpose, and that there might be no failure in so essential an article, a double course of pipes in stone and mortar was laid. In this way a column of water the size of a man’s body was conducted into the heart of the capital.”[302]