I believe that CATS has several K37s, but none are operating or being considered for rebuilding.

The main issue with the K37s is that they were built by DRGW using the salvaged boilers off surplus standard gauge 2-8-0s. So while the K-37s are the youngest DRGW narrow gauge steam engines, they have the oldest boilers of all the DRGW narrow gauge K class.

Whether you are talking about CATS or DSNG, as each engine comes due for heavy repairs (especially the FRA 1472 recertification) or has a major failure, they have to decide which engine is the most economical to rebuild next. Sometimes a substantial grant/donation towards a specific engine will influence their decision, such as the recent return of the 463 to service. Never say never, a K37 may again run over Cumbres Pass but not anytime soon.