The Denver and Rio Grande Western K-37 is a class of 2-8-2 "Mikado" type narrow-gauge steam locomotives built for the Denver and Rio Grande Western Railroad. They were all new steam locomotives built in the D&RGW Burnham Shops as a cheaper option to new Baldwin K-36s. Burnham Shops was assisted in the construction of the class by the Stearn-Rogers Manufacturing Company. The class used components recycled from Baldwin Locomotive Works built Class 190 (later C-41) 2-8-0 locomotives used on the Rio Grande's standard gauge; re-using the boiler, tender and other components salvaged from the C-41's. The engine components; particularly the valve gear, were constructed new for the locomotive class.