Dolomite with some limestone and shale; includes Galena, Decorah, and Platteville Formations
Orthoquartzitic sandstone with minor limestone, shale and conglomerate; includes Glenwood and St. Peter Formations
Dolomite with some sandstone and shale; includes Shakopee and Oneota Formations
Sandstone with some dolomite and shale, undivided; includes Trempealeau, Tunnel City, and Elk Mound Formations