Toppa Tin Mill. Emerging from the morning shadows at the top of Tin Mill Hill, Black Hills Central Railroad Locomotive #110 blows for the 3rd crossing of Old Hill City Road near Milepost 1, on the eastbound run from Hill City, SD, to Keystone, some 9 miles from here. The pretty morning light at this location nicely illuminates the brutish lines of this massive log-hog, and with her 7-car passenger train still dangling down the 4-6% grade, she's still working pretty hard. You won't always see smoke from this oil-fired beast here, but the odds are pretty good. With her water supply centered right over her two pairs of drivers, this is one of the few rod engines in existence that could handle this train on this line. Although she's hardly a prototypical passenger engine, she's ideally suited to this operation and it is no surprise that when the Black Hills Central went looking for a second heavy locomotive a few years back, they chose another, virtually identical Baldwin 2-6-6-2T Compound Mallet, which runs today as Black Hills Central #108.