Antonio de Espejo
In February 1583, Espejo arrived at the territory of the Piros, the most southerly of the Pueblo villagers. From there the Spanish continued up the Rio Grande. Espejo described the Pueblo villages as "clean and tidy". The houses were multi-storied and made of adode bricks. "They make very fine tortillas," Espejo commented, and the Pueblos also served the Spanish turkeys, beans, corns, and pumpkins. The people "did not seem to be bellicose". The southernmost Pueblos had only clubs for weapons plus a few "poor Turkish bows and poorer arrows". Further north, the Indians were better armed and more aggressive. Some of the Pueblo towns were large, Espejo described Zia as having 1,000 houses and 4,000 men and boys. In their farming, the Pueblos used irrigation "with canals and dams, built as if by Spaniards". The only Spanish influence that Espejo noted among the Pueblos was their desire for iron. They would steal any iron article they could find.
San Juan River (Colorado River tributary)
The San Juan River and its tributaries were an important water source for Native Americans as early as 10,000 BC, when Paleo-Indians inhabited the Four Corners region. By 500 BC–450 AD, the Basketmaker culture was succeeded by the Ancestral Puebloans or Anasazi who developed distinctive irrigation methods and masonry architecture ("pueblos"); many ruins and sites are preserved in the San Juan watershed in places such as Mesa Verde National Park. Most settlements were concentrated along the upper San Juan River in New Mexico, where the terrain is gentler and water more abundant. The lower San Juan River in Utah flows through inaccessible canyons that largely precluded habitation. Starting around 1300 AD, a warming climate brought long droughts to the area, forcing the Puebloans to abandon their settlements north of the San Juan River, and eventually causing them to migrate out of the San Juan River basin to the Rio Grande Valley, where their descendants live today.