The K-27 class was the last compound locomotive built for D&RGW. The “K” stood for “Mikado” and the number for starting tractive effort of 27,000 pounds. Its engine had four cylinders and was of the Vauclain type, but was replaced by a simple two-cylinder engine just four years after delivery. As with other narrow-gauge locomotives of the D&RGW, the axles were in an outer frame. The nickname “Mudhen” came about because with the original engine they often derailed. Most K-27s were scrapped in the fifties and the last two built still exist today. The No. 463 runs on the Cumbres & Toltec Scenic Railroad and the No. 464 is owned by the Huckleberry Railroad and last ran in 2019.