Navajo build polygonal buildings of stacked logs, called hogans, and the Apache versions are called wikiup. Among Anasazi peoples large urban areas are favored. These are mud and stone walled multi storied houses often without street entry, but entered from rooftop openings. Prehistorically, they had been built against cliffs, but prior to contact these indians had begun building towns on valley floors. These are known by the Spanish word for town Pueblo.
Pueblos come in two forms, either parallel street forms, or plaza forms.
The thick walls are heated during the day by the sun and then warm the inside of the house at night with the stored heat. Indians of the northern California valleys and foothills built plank houses grouped in towns, similar to northwest coastal traditions. Along the Colorado river areas Yuman speakers built sand roofed houses, with granaries built on top, or alongside. The Alaskan Arctic is part of a much larger cultural region that stretches across the entire polar area. Within this area dwelling are uniformly divided between summer and winter homes.