Material · lithic

Knife River flint

North America — Great Plains

Knife River flint is the dark brown, translucent silicified lignite from western North Dakota that was quarried from Paleoindian times and traded across the Plains and into the Hopewell world. It is the premier material of Northern Plains prehistory. Cody, Pelican Lake and Besant points in it are especially collected.

Kindlithic
RegionsNorth America — Great Plains

Sources

The primary quarries lie in Dunn and Mercer counties, North Dakota, near the Knife River, where thousands of quarry pits are preserved; cobbles also occur in glacial and river gravels across the Dakotas and into Manitoba and Saskatchewan. It formed as silicified peat in Paleocene sediments.

Identification

The stone is coffee to root-beer brown, translucent at the edges, with a glassy lustre and occasional plant fossils; weathered surfaces develop a light tan or whitish patina. It is easily confused with brown chalcedonies from Montana and Texas. Freshly broken surfaces are uniformly dark.

Substitutes and fakes

Modern knappers use Knife River flint widely, and the glassy fresh surface of a new point contrasts with the patinated rind of an old one. Smoke-blackening is sometimes applied to imitate hearth exposure.

Cite this article

Stratum Study. "Knife River flint" (Material). Stratum Study pack 2026.09, as of 2026-09-21. https://stratum.black/study/materials/knife-river-flint. Accessed 2026-09-21.

@misc{stratum-knife-river-flint,
  title        = {Knife River flint},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/materials/knife-river-flint}},
  year         = {2026},
  note         = {Material article, Stratum Study pack 2026.09, as of 2026-09-21; sources: stratum. Accessed 2026-09-21.}
}

Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.

Sources for this article: Stratum editorial (Stratum editorial). As of 2026-09-21; Study pack 2026.09. Data reproduced under the licences shown; text in Stratum's own words unless a section names its source.

Found an error? Write to drew@tyr.ac with the article id material:knife-river-flint.

Stratum is the inventory, provenance and certificate system for fossil, mineral and shell collections. Study is its open reference: every fact cites its source, and the credits page lists each one with its licence.