• Ordovician-Silurian Subcrop/Outcrop Williston Basin (GIS data, line features)
• Ordovician-Silurian Structure (GIS data, line features)
• Ordovician-Silurian Structure (GIS data, polygon features)
• Sweetgrass Arch and Williston Basin Tectonic Elements (GIS data, line features)
• Upper Cambrian - Lower Ordovician Lithology Shale (GIS data, polygon features)