A mule deer buck stands atop the slag wall off South Montana Street in Butte recently. A passer-by in a vehicle, Peggy Poling Sharkey, who lives near Boise, Idaho, snapped this photo and emailed it to The Standard. Poling said the deer appeared to be watching traffic. The slag walls were built during the early 1900s as a byproduct of copper ore smelting at the Butte Reduction Works, according to the Montana Tech Department of Geological Engineering.