The catlinite, or pipestone, was and is used to make peace pipes, vitally important to traditional Plains Indian culture. The quarries are sacred to the Dakota Sioux (Lakota) Native Americans, and were neutral territory where all tribes could quarry stone for ceremonial pipes. The Sioux tribes may have taken control of the quarries around 1700, but the Minnesota pipestone has been found inside North American burial mounds dating from long before that, and ancient Indian trails leading to the area suggest pipestone may have been quarried there for many centuries.
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Complex geological site in which the underlying bedrock is a metamorphosed sandstone generally referred to as Sioux quartzite, regarded as early Ordovician in age. Significant as center of Indian activity for centuries; used quarry for pipe stone and other stone artifacts. Was and continues to be used by the Indians as a source of materials important for various practical and ceremonial purposes.
Source: HAER