Jeff, Ononadaga is found on an escarpment that roughly runs from Niagara Falls to Albany then turns south an heads into Pa. Roughly rt.20 from Buffalo to Albany. I am not computer savy but there are guys who goggle earth an you can some how see this escarpment line an places where streams or highway cuts go thru this they cut rock outcrops an expose rock, Of course with any type rock there are all kinds of grades an problems,frost fractures blasting fractures,to name just a few. Some Onondaga is a pleasure to work an is high grade stuff. Actually the few pcs, that i have came from the Candian side of Niagara Falls area. Also when you first crack open Onondaga it has a high petroleum smell to it, thus the nickname of stinkrock. Check out Dan Long's website for some beautiful Onondaga blades an points