Tan to orange clay, silt, and sand with a large amount of basal gravels.
Gray to brownish gray clay and silty clay, reddish brown in the Red River Valley, some sand and gravel locally.
Gray to dark gray calcareous clays which may weather to black soil; lignitic clays and noncalcreous clayey silts
Yellow to gray siltstones, sandstones, and clays with thin tuffaceous beds; some lenses of black chert gravel; petrified wood locally.
Gray to yellow silty clays; light gray calcareous clays which may weather to black soil; some siliceous silt and volcanic ash beds.
Gray to green silty clays, siltstones, and silts with abundant sand beds; some lignite and lenses of black chert gravel.
White to gray silts, siltstones, silty clays, and sand beds; some lenses of black chert gravel.
Light gray to orange-brown clay, sandy clay, and silt; much sand and gravel locally.
Light gray to light brown clay, sandy clay, silt, sand, and some gravels.
Gray mixed with brown-to-red clay and silty clay; some sand and gravel locally.
Gray calcareous clays which may weather to black soil; siltstone, taffaceous clays and some volcanic ash beds
Gray to white sandstones; loose quartz sand, tuffaceous sandstone, volcanic ash, and brown sandy clays; petrified wood locally.
Alluvium
Brown to gray liginitic clays with thin interbeds of lignite or micaceous sands; calcareous shale, petrified wood, and bluish fossilferous clay locally.
Deweyville Formation
Fleming Formation