Arizona's Four Main Land Regions

1. Colorado Plateau (N): High plateaus, canyons (Grand Canyon).
2. Basin and Range Province (Central/S): Alternating basins and mountain ranges.
3. Sonoran Desert (S): Saguaro cacti, unique flora/fauna.
4. Transition Zone (Central): Ecotone between Plateau and Desert.

These regions create Arizona's dramatic ecological and topographic diversity.