Gray to brownish gray clay and silty clay, reddish brown in the Red River Valley, some sand and gravel locally.
Tan to orange clay, silt, and sand with a large amount of basal gravels.
Gray and brown silt, silty clay, some very fine sand, reddish brown along the Red River.
Light gray to light brown clay, sandy clay, silt, sand, and some gravels.
Light gray to orange-brown clay, sandy clay, and silt; much sand and gravel locally.
Yellow to gray siltstones, sandstones, and clays with thin tuffaceous beds; some lenses of black chert gravel; petrified wood locally.
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. Overlain by 1-9 meters of loess.
Gray to yellow silty clays; light gray calcareous clays which may weather to black soil; some siliceous silt and volcanic ash beds.
Light gray, tan and brown fine to coarse sand; some clay silt and gravel.
Tan to orange clay, silt, and sand with a large amount of basal gravels. Overlain by 1-9 meters of loess.
Gray to dark gray calcareous clays which may weather to black soil; lignitic clays and noncalcreous clayey silts
Gray to green silty clays, siltstones, and silts with abundant sand beds; some lignite and lenses of black chert gravel.
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.
Light gray to light brown clay, sandy clay, silt, sand, and some gravels. Overlain by 1-9 meters of loess.