So I tried to make another rock column. This one is twice the width of the other as per the picture of the actual formation that I have. It still took too many hours to produce and I still need too many of them. My next choice will be to form Sculptamold rock formations in place. I think that will reduce the time since I won;t have to custom fit each column to the ravine contours. That took almost an hour putting on the backing pieces and shaping the rock so it nestled somewhat into the ravine's plaster base.