What was a defining feature of settlements in the Southwest region?

The defining feature of settlements in the Southwest region was the construction of caves and cliff dwellings. This architectural style is exemplified by the Ancestral Puebloans (formerly known as the Anasazi), who developed intricate cliff dwellings in places like Mesa Verde and the canyon walls of the Southwest. These constructions provided protection from the elements and enemy attacks, while also utilizing the natural topography for added security and insulation.

The choice of cave and cliff dwellings reflects the adaptation of these communities to their environment, where they utilized local resources and landscapes effectively. It also highlights the advanced engineering skills of the indigenous peoples who lived in these regions, showcasing their ability to create stable, durable living spaces that could withstand the challenges of their landscape.

Other options do not accurately capture the distinctive characteristics of Southwest settlements. For example, the use of heavy timber and stone is more representative of other geographical areas where such materials were readily available and often used in construction. Likewise, large populations in single structures would not accurately reflect the dispersed nature of many Southwest settlements due to environmental constraints. Finally, the notion of isolation from other cultural groups does not align with the historical interactions and trade networks that existed among different indigenous peoples in North America.