Named as a member of Swede Hollow Formation (named) of Cherokee Group of Des Moines Supergroup for locality called Wheeler Bridge which formerly stood in NW1/4, NE1/4 sec 33, T73N, R22W, Lucas Co, IA on the Iowa shelf. The outcrop at this locality is the type section. The interval of gray, pyritic shale and gray, fine grained, cross-bedded sandstone between the Wheeler and the younger Bevier Coal Member is usually less than 20 ft thick. Overlies unnamed rooted shales of the Swede Hollow. Variable in thickness; seldom exceeds 2 ft thick. Described as a weathered coal at type exposure of the Swede Hollow. Nomenclature chart. Graphic section. Cross section. Assigned to the Pennsylvanian, Desmoinesian age.

Source: GNU records (USGS DDS-6; Denver GNULEX).