...known region in the north. They seem to have first halted in their migrations southward at the Great Salt Lake in Utah; the next on the River Gila; and the last on the high plateau in the valley of Mexico , where they led a nomadic life until early in the fourteenth century, when they laid the foundation of a city upon an island in Lake Tezcuco, and called it Tenochtitlan; afterwards Mexitli (Spanish, ...