2-6-6-2T No. 110 Black Hills Central Railroad articulated Mallet.

2-6-6-2T No. 110 Black Hills Central Railroad (BHC) articulated Mallet. Pulling a tourist train from Hill City, SD on the way to Keystone, SD. The 2-6-6-2T No. 110 is the only Mallet in service in the world. - July 21.2015