The badlands of North Dakota are dotted with outcroppings of red stone that is locally called scoria.  Scoria point is a very large deposit in the south unit of Theodore Roosevelt National Park.  Layers of clay adjacent to coal layers are potential for a burning coal vein.  When a coal layer is ignited, it bakes the clay into a flower pot type rock that clinks when it is dropped, hence another nickname for the red rock, clinker. When the sun sets, the orange light reflecting off Scoria point seems as tho the red rock glows from within.  Well my dog is barking at me, need to run