Plains state varies from nearly level farmland to hill ridges, increasing steadily in elev. From 1,000’...beds, excavations, etc.Selenite roses. BRULE COUNTY AREA: in the Oacoma zone of the Pierre Fm. On Elm...gray Barite rosette up to 5 or 6 inches. CAMPBELL COUNTY MOUND CITY, W to the Missouri R., regional hillsides...gravels, etc.petrified wood, wood opal. CORSON COUNTY LITTLE EAGLE: area ridges, slopes, stream beds...Guide for Rock Hounds in the United States CUSTER COUNTY AREA: The November Mine, 1.2 mi. SE of the Needles |