Earth lodge

An earth lodge is a semi-subterranean building covered partially or completely with earth, best known from the Native American cultures of the Great Plains and Eastern Woodlands. Most earth lodges are circular in construction with a dome-like roof, often with a central or slightly offset smoke hole at the apex of the dome. Earth lodges are well-known from the more-sedentary tribes of the Plains such as the Hidatsa, Mandan, and Arikara, but they have also been identified archaeologically among sites of the Mississippian culture in the eastern United States.

Earth lodges were typically constructed using the wattle and daub technique, with a thick coating of earth. The dome-like shape of the earth lodge was achieved by the use of angled (or carefully bent) tree trunks, although hipped roofs were also sometimes used. During construction the workers would dig an area a few feet beneath the surface, allowing the entire building to have a floor somewhat beneath the surrounding ground level. They set posts into holes in the ground around the edges of the earth lodge, and made the tops meet in (or near) the middle. This construction technique is sturdy and can produce large buildings (some as much as 60 feet (18 m) across), in which more than one family would live. Their size is limited by the length of available tree trunks. Internal vertical support posts were sometimes used to give additional structural support to the roof rafters.

After a strong layer of sticks (or reeds) was wrapped through and over the radiating roof timbers, the people often applied a layer of thatch as part of the roof. The structure was then entirely covered in earth. The earth layer (and the partially subterranean foundation) provided insulation against the extreme temperatures of the Plains. The structures consisted of a clay outer shell over an inner shell of long grasses and a woven willow ceiling. The middle of the earth lodge was used as a fire pit, and a hole was built into the center. This smoke hole was often covered by a bullboat during inclement weather. Logs were gathered each spring as the ice receded and sheared them off; fresh logs were also cut. The most common wood used was cottonwood. Cottonwood was a wet, soft wood; this meant that lodges often required rebuilding every six to eight years.

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