BHCR #110, a Compound, Articulated Mallet Tanker. Yes, the 110 is one of just two such 2-6-6-2T locomotives that are in operation in the US today. The other is at Niles Canyon in California. This engine has two sets of drivers, the rearmost of which is the high-pressure set, and the foremost is the low-pressure set. Steam exhausted from the aft set is then piped forward and re-used in the forward set. Needless to say, that forward set of drivers is most efficient when the she's up to speed. The locomotive articulates, allowing her to negotiate tight curves, despite appearing to have a very long wheel base. With her water supply sitting right over the top of her drive wheels, she's capable of developing 37,500 lbs of tractive effort....and she needs all of that to haul 7 loaded coaches up the 4-6% grades on Tin Mill Hill. This locomotive is quite a treat to watch and listen to. If you're ever up in the Mt. Rushmore area, be sure to stop by the Black Hills Central and take the ride. Sit up front in the lead coach for the trip back to Hill City from Keystone and you'll get to see just how much this big saddle-tanker really articulates.