Almost all we've found is from local source rock. Chert nodules embedded within St Louis and/or St Genevieve Limestone formations. These are formations usually 300ft thick. Accessed from outcroppings or at the base of bluffs along the rivers. Liberated by ancient man from exposed rock walls or salvaged from creek nodules. Some are heat treated from being buried under coals. This gives the parent nodule a cooked, glassy composition. Easier for concodial fracture and final flaking.
Obviously there is some 'trade rock' near the river systems. Renegade has a place that has some different pieces and colorations. Pinks and oranges. Those can also be attained by further heat treating techniques.
