The sediments are layered in horizontal beds that vary in thickness. In the upper 25 cm of the unit, stratification may be disrupted by plant rooting and animal burrowing. Modification of the sediments by soil formation is minimal Is thickest in areas adjacent to the modern channel. Usually buries the presettlement soil. Dates from 400 years before present to modern times.
Unit lacks stratification except in the lower, coarser part.
Unit is found on modern floodplains, generally in a narrow belt paralleling the modern channel. Sediments were deposited between 4000 and 500 years before present. Unit is usually found beneath low terraces slightly elevated above modern floodplains. The surface expression of the terrace is often subdued because of an overlying mantle of Camp Creek Member sediments. Radiocarbon ages from the unit range from about 10,500 to about 3,000 years before present.