Why were high valleys and lake regions important settlement areas for Middle American Indigenous peoples?

High valleys and lake regions were essential settlement areas for Middle American Indigenous peoples primarily because water is the fundamental requirement for human life. Since prehistoric times, major river systems and high-valley lakes served as the primary sites for habitation.1

These regions offered several strategic advantages:

• Agricultural Productivity: The mild climate and ample water supply in areas like the Valley of Mexico allowed for intensive cultivation. Indigenous groups, such as the Aztecs, utilized these water sources to create chinampas—highly productive "floating gardens" that enabled multiple harvests annually.2
• Subsistence: Beyond crop cultivation, such as the corn-bean-squash triad, lake environments provided diverse food sources, including aquatic resources and game animals.3
• Transportation and Unification: Systems of connected lakes and canals facilitated water transportation, which was critical for the economic and political unification of regions like the Valley of Mexico.2

The high valleys of central Mexico, Oaxaca, Jalisco, and Guatemala became the most densely settled parts of Middle America due to these favorable ecological conditions.1