Lithic Sourcing

Archeologists guide to toolstone sources.

Knife River Flint

The primary source area is in west central North Dakota, especially Dunn and Mercer counties. Significant quantities are found in a wider part of this region. KRF has been documented as very rarely occurring in the form of scattered small cobbles and pebbles beyond the primary and secondary source areas, including the southern half of Minnesota and north central Iowa.


Distinctive "coffee" color. Slightly cloudy appearance in all but thin flakes. Internal whitish mottled inclusions are thought to be fossil plants, possibly cat-tail leaves. Patina, when present, white to bluish white. Fine grain, reveals good flake morphology. Cortex is usually yellowish white, coarse, laminated. Burned KRF is grey and opaque, although the characteristic brown color is usually still apparent in transmitted light.

Caption describing picture or graphic.

Eocene - Golden Valley Formation


Diana Rose Angelo, M.A., R.P.A.


Electronic Links:
Geologic Time and Context:
Geographic Location Map:

Clair county, IL

Cass county, MN

Archeological Site Locations:

Ahler, Stanley A., and Julieann Vannest

1984 Temporal Change in Knife River Flit Reduction Strategies. In Lithic Resource Procurement: Proceedings from the Second Conference on Prehistoric Chert Exploitation, edited by Susan C. Vehik, pp. 183 – 198. Occasional Paper No. 4, Center for Archaeological Investigations, Southern Illinois

University, Carbondale.


Clark, Francis 1984 Knife River Flint and Interregional Exchange. Midcontinental Journal of Archaeology 9(2):173-198.


Clayton, Lee, W.B. Bickley, Jr. and W.J. Stone 1970 Knife River Flint. Plains Anthropologist 15(50):282-290.


Gregg, Michael L. 1987 Knife River Flint in the Northeastern Plains. Plains Anthropologist 32(118):367-377.


Loendorf, Lawrence L, Stanley A. Ahler and Dale Davidson 1984. The Proposed National Register District in the Knife River Flint Quarries in Dunn County, North Dakota. North Dakota History: Journal of the Northern Plains 51(4):4-20.