Answer:
Because the natives in the Southwest "adapted to there environment"
Explanation:
Because they lived in desert biomes, they decided that it would be easier to build with Adobe rather then with wood from trees. Overtime they found a way to eventually grow crops in a desert environment.
Same thing with the Northwest, they adapted to there environment and built with wood instead of adobe cause they didn't live in desrt environments.
The climate east of the Cascades is markedly different, a continental climate of cold, snowy winters and warm, dry summers. ... Climate also affects growing seasons in the Columbia River Basin. At higher elevations, the season can last as few as 30 days.
