There are, Texas Hill country is littered with exposed limestone (and even more unexposed). Karst topography if you feel like googling it. In fencing you can go 30 feet before you can get a t post planted 6" in the ground so we drill instead. Ill try to get some representative pics of what Im cutting and where this weekend but they are forecasting oppressive heat so I might not remember since I doubt Ill cut.Like you said, must be a LOT of rocks. Glad the comparatively cheapo saw blades are working. I'd forgotten how expensive the brush blades were.